This is “experts” week for our stroll back through various posts on this blog.  In September 2017  barrister Brian McCluggage for sent me a copy of the decision of Her Honour Judge Belcher in Hatfield -v- Drax Power Ltd (18/08/2017) which contains robust criticisms of a witness called on behalf of the claimant in that case.  (Brian also told me that the claimant agreed to pay the second defendant’s costs on an indemnity basis from the date of exchange of witness statements.


(I have attached a copy of the full judgment here. Hatfield v Drax Power and SG Transport 17.08.18.judgement).


“That arrogance came over in  the  witness box.  He  plainly felt  he  was  right and everyone  else  was  wrong.  Indeed,  I  made  a  comment  to  that  effect during the  course of  his  evidence. Furthermore,  after  he  had  completed  his  evidence,  he  sat  in  the  well of the court shaking  his  head  from  side to  side,  evidencing  his  disagreement,  and, judging by  his  face,  his  disgust,  with  the  evidence  being  given  by  Mr  Mutch,  the  first of the Defendant experts to be called.”


The claimant was driving an articulated vehicle that came off the road causing him serious injury. His case was that this was due to the road surface and defective tyres.  Expert evidence was called by both parties.


“The  Expert Evidence
46. I now  turn  to  the  expert  evidence,  at  this  point  solely as to the  extent,  if any,  to which it assists me in determining the condition of the road at the time of the In my judgement it is instructive to start with the order  granting  permission  for  the  calling  of expert evidence.  That  appears  at B1: 74-76.  In that  order the  Claimant  has  permission to rely upon evidence from  Professor  Vantsevich  “…  in  respect  of  vehicle  dynamics  and stability”. The First and Second Defendants have permission to rely upon  expert evidence of Mr Damien  Mutch and  Dr  Darren Walsh  respectively,  in  each case  “…as to causation of the accident”. The reports of Professor Vantsevich address  specific questions  that he  was asked  and  in  particular,  (i)  whether  a   difference   in circumference  of  the  tyres  had  the  potential  to  affect  the  differential  and  cause  lock- up,  and  (ii)   if  so,  what  effect  that  would  have  had  on  the  handling  of  the  vehicle and(iii) whether the wet/muddy  road  surface  would  have  had  an effect  on the  handling  of  the  truck especially  if  the  differential  had  locked.  It  is  unsurprising,   against   that request,  that his   report  is   highly  technical  and  principally  deals  with  issues  in  relation to the diameters of the tyres  and/or  issues  said  to  have  arisen out of re-cutting,  and  on the  effect  of those  matters  on the  vehicle handling.
47.I recognise  that English  is  not  Professor  Vantsevich’s   first   language   although   he works and lives  in  the  United States.   He  claimed  to  understand  his  duties  as  an expert as set out in CPR Part 35 a copy of which had been provided  to  him.  I am in no doubt  at all that he had no proper understanding of his duties as an expert. In the course of cross-examination, he accepted that  the  theory  he  was  putting  forward  was  precisely that, theory and only one possible explanation for the accident. He said that he simply responded to the questions in his instructions. He made no attempt to evaluate  the  alternatives and, in particular, the alternative explanations for  the  accident  being  put  forward  by the  defence experts.
48.Professor Vantsevich’s  evidence  was  extraordinary in  its  presentation  and,   frankly, shot  through  with  breath  taking  arrogance.  His  stance  throughout   was  that  he   was right and everybody else was wron. That stance appears, first  of  all,  in  the  joint  statement of  the  experts  in  the  following  extracts.  Professor  Vantsevich  “….observes that Dr Walsh and Mr  Mutch  need  to  take  an  undergraduate university course  on vehicle dynamics  to understand the  assumptions  and  their  relevance  to  the circumstances  of  the  incident.”  (B2:889,  paragraph;   “…   Strongly recommends the  [defence]  experts  to  attend  a  vehicle dynamics  course  to  understand the subject matter of Professor Vantsevich’s report (B2:890, paragraph; “…. Would like to point out that the two [defence] experts also have problems with  understanding both the second law and the third law of Newton…(B2:894,  paragraph 3.7.2); and “…encourages them to learn the engineering meaning of “possible” and “probable”.”  (B2:901,  paragraph 3.19.3).
49. The same arrogance is self evident in his replies to Part 35 questions put to him by the Second Defendant. In rejecting one  point  put  to  him  for  comment,  he  goes  on  to assert that his response is “high school physics” (B2:712, Answers  to  10.2).  In  other places he fails to  assist  the  court  by dealing with the  matters  put  to  him.  At  question 9, he was asked to assume that the trial judge finds as a fact that the tyre patterns on the  surface of the road  show  a  clear  pattern  without  signs of  skidding,  and  he  is  then asked whether such a finding would invalidate his hypothesis. Rather than answer  the question, he simply says  “I  cannot  accept  your  weak  hypothesis  to  find  a  “clear pattern without signs of skidding” (B2:711, Answer to 9.1) . Not only does that fail to answer the question, it  also  fails  to  recognise  that  it  is  for  me,  as  the  judge,  to  make the  findings   of fact  in  this case.
50.That arrogance came over in  the  witness box.  He  plainly felt  he  was  right and everyone  else  was  wrong.  Indeed,  I  made  a  comment  to  that  effect during the  course of  his  evidence. Furthermore,  after  he  had  completed  his  evidence,  he  sat  in  the  well of the court shaking  his  head  from  side to  side,  evidencing  his  disagreement,  and, judging by  his  face,  his  disgust,  with  the  evidence  being  given  by  Mr  Mutch,  the  first of the Defendant experts to be called. I made it clear to Professor Vantsevich that that behaviour  was  unacceptable  and  whilst,   on  the  whole,  he  managed  to  contain  himself, I did catch him on further  occasions  shaking  his  head  at  the  evidence  given. That conduct is wholly discreditable to an expert witness in our courts. I have never  seen it before,  even in  cases where  experts  are poles  apart in their opinions.
51. Further, by the end  of  Professor  Vantsevich’s  evidence,  the  whole  of  his  case  based on a difference in diameter as  between  the  tyres  on the  drive  axle  of the  Tractor  Unit had   fallen   away,   not  because  Professor  Vantsevich  resiled   from  it,   but  because  Mr Pennock was forced to concede that the other evidence  in  the  case  was  such that  he could  not succeed  on a case based on any difference   in  the  diameters  of the tyres.
52. Professor Vantsevich conceded in the witness  box  that  he  was  wrong  about  the  first two troughs in the tachograph representing slippage of the wheels and that the  defence experts were correct in saying those troughs represented the vehicle slowing prior to manoeuvring around bends in the road.   It has to be said  that  this  concession was first  made (and properly so)  by  Mr  Pennock  on day 2  of the  trial.  Professor  Vantsevich  first made the concession in the witness box, notwithstanding  his  refusal  to  accept  this point in the joint expert report in yet  another  paragraph  referring  Dr  Walsh  and  Mr Mutch  to a university  course  on vehicle   dynamics (B2:893,  paragraph
53. Prior to trial Professor Vantsevich had refused to accept that there was a  five  second period of acceleration prior to the collision and had insisted there was only one second (B2:412, paragraph  5).  From  the  witness  box  he  suggested  that was  a typographical  error, an explanation  I found   less  than convincing.
54.Prior to the trial Professor  Vantsevich  prepared  his  report  expressly  on  the  basis  that the lift axle was lowered at the time of the In  the  joint  report  Professor Vantsevich accepted that  the  lift  axle  was  in  fact  raised  at  the  time  of  the  accident (B2: 888, paragraph 2.2). The effect of that was that the calculations that  he  done  in relation to the friction coefficient of the drive axle when compared to the peak friction coefficient were wrong. The calculations  depended  upon  the  mass  borne  by  the  drive axle, and how that mass is  spread  across  the  tractor  unit  axles  will  depend  upon whether the mass is spread  between  two  axles  only  (with  the  lifting  axle  raised)  or across three axles with  the  lifting  axle  lowered.  Prior  to  the  trial Professor  Vantsevich had not  bothered  to  re-do  the  calculations  to  address  the  factual change.  Indeed when it  was  put  to  him  in  cross-examination  that his  calculations   were  done  on  the  basis that all three axles  were  in  contact  with  the  ground,  his  first  response  was  that  he  would need to  check  that.  When  some  surprise  was expressed  by defence  counsel that he did not appear  to  know the  basis  on which his  own report was put before  the  court he then said “It  is  most  likely  I  did  the  calculation  with  the  axle  raised”.  I  regret  this was typical of the totally defensive  and  unhelpful attitude  evinced  by  Professor Vantsevich  throughout   his  evidence.
55. Having re-done the  calculations  overnight,  the  effect  was  to  change  the  calculation  from one where Professor Vantsevich had concluded that  25%  of  the  available reservoir friction had been used (hence on his case inevitably allowing slippage on the mud/slurry), to one where 44% of the  available  reservoir  friction  had  been  used.  In answer to questions the previous day (before he had done his recalculation) Professor Vantsevich agreed that if the ratio reduced from  95  or  96%  to  say  50%,  then  the degree of slippage would be very much  less.  Asked  if  he  would  agree  that  if  the  ratio was about 60% the truck would be  reasonably  stable  with  only  modest  risk  of  slippage, Professor Vantsevich said “I would say it’s on the edge of risk. If the  current friction coefficient is 55% – 60% of peak  friction  coefficient,  a  tyre  in  poor  road conditions can start skidding aside.  At  33%,  he  said  the  driver  is  safe  in terms  of the risk  of tyre slippage.
56. Professor Vantsevich redid his  calculations  overnight  to  reflect  the  raised  lift  axle  and that produced  a  ratio  of  44%.  Notwithstanding  the  answers  given  the  previous  day that  55  to  60%  would  be on the  edge  of risk,  Professor Vantsevich maintained  that the ratio of 44% still  produces  a  very  high  risk  of  slippage.  He  told  me  the  ratio represents an exponential curve rather than a straight line on  a  graph, such  that  an increase from 33% to 40% is  a  very  significant  increase.  In  my  judgement  that  was clear evidence of Professor Vantsevich seeking to maintain a case on behalf  of  the Claimant rather  than  genuinely  assisting  the  court.  No  doubt  he  would  have  been hugely embarrassed to admit that having done the proper calculation, he was in some difficulty sustaining the case,  but  that  is  the  proper  and  responsible  course  of action  to be taken by an expert properly carrying out his duties  to  the  court.  Mr  Cowan  described this conduct by Professor  Vantsevich  in  relation  to  this  particular  issue  as  most egregious. I agree.  All of the  factors  I have  set out  militate  against any findings  based on the  expert  evidence   given  by Professor Vantsevich.
57. In his  closing  submissions  Mr   McCluggage   described   Professor  Vantsevichs approach in his  reports  as  advocating  a  theory  rather  than  investigating  the  accident, and  that  it  is  for  that  reason  that  Professor  Vantsevich  fails   to  give  any  consideration to  other  potential  causes  for the    In  my  judgement  that is   an  entirely accurate  and  proper  criticism  of Professor  Vantsevichs  evidence. Far  from being  here to assist the court,  in  my  judgement  Professor  Vantsevich  was  here  to  advance  a theory  and  to promote  the  Claimant’s case.
58. Both defence  counsel  made  other  points  of  valid  criticism  against   Professor    I  consider  it  unnecessary  to  go  through  any  further  points.   It  seems  to me that the  whole  instruction  of  Professor  Vantsevich  was  ill-conceived,  and  that  a great deal of money and court time has been wasted by the manner in which he has approached  this  case and  in  which  he gave  his evidence.”


Later in the judgment the judge considered the views of the defendants’ experts and concluded:-

“I have no hesitation in accepting  the  evidence  of  the  defence  experts  in  preference  to the evidence of Professor I reject Professor  Vantsevich’s  theoretical possibility, particularly in circumstances where he  accepts  that he  was,  in  effect, instructed simply to explore that as  a  possibility.  He  was forced  to  accept there  could have been other reasons for this accident. He told me his theory is  one  of  a  100 possibilities. Asked how his theory stands  up  in  the  absence  of repeated  accidents  or other problems on the Road, Professor Vantsevich resorted to this being a particular combination of circumstances which  had  all  happened  to  come  together  for  that  truck on that Road. He said it will happen again one  day.  I regret that  these  answers  were wholly implausible, clutching at  straws  in  my  judgment   to  support  his   theory  which had collapsed  under  sustained   forensic  cross examination.”