WHEN WITNESSES ATTEMPT TO GIVE EXPERT EVIDENCE: LOOK OUT FOR THOSE PURPLE PASSAGES
This blog has reported on numerous cases where lay witnesses have attempted to give expert evidence (and, indeed, where expert witnesses have tried to give evidence of matters of fact). This issue can be seen in the judgment of Lord Justice Arnold in Glaxo Wellcome UK Ltd & Anor v Sandoz Ltd & Ors  EWHC 2545 (Ch).
The claimant was bringing an action claiming that the use of the colour purple in the packaging of certain medication.
THE “STATE TRIAL”
The judge commented on the way in which the parties had approached the litigation.
Although Glaxo commenced these proceedings as long ago as December 2015, the claim has had an unfortunate procedural history which meant that it only reached trial in July 2019. Regrettably, both sides have approached the matter as if it were a State Trial: there was a great deal of interlocutory skirmishing which continued right up to trial, a large volume of both documentary and witness evidence was produced and I received extensive written and oral submissions. It is not necessary for me to refer to all of this material in this judgment, and large parts of the documentary evidence turned out to be of little significance for reasons that will appear.
THE JUDGE’S COMMENTS ON THE WITNESS EVIDENCE
Reading the judgment it appears probable that much time (and money) was spent in preparing witness statements which were of limited assistance.
Even though a number of witnesses were dropped, I received evidence from a large number of factual witnesses: six employees or former employees of Glaxo; four solicitors employed by Glaxo’s solicitors; six employees or former employees of Sandoz, Aeropharm and/or Hexal; one former employee of Vectura; four respiratory consultants; one junior hospital doctor; seven general practitioners (“GPs”); 13 pharmacists (two of whom were independent prescribers and two of whom were employed by Clinical Commissioning Groups, “CCGs”); one nurse independent prescriber; one physician associate; one regulatory affairs consultant; and one data analyst.
The first is that, prior to the trial, Sandoz sought permission to adduce expert evidence from a respiratory consultant, a GP and a pharmacist. This application was successfully opposed by Glaxo, which contended that the relevant evidence could and should be given by factual witnesses giving so-called “trade” evidence (as to which, see in particular Fenty v Arcadia Group Brands Ltd  EWHC 1945 (Ch),  Bus LR 1165). Subsequently, the Defendants objected to the admissibility of substantial parts of the witness statements served by Glaxo on various grounds, but in particular that some of the statements were in substance expert evidence and that parts of others amounted to expressions of opinion, and in particular speculation by the witnesses as to the thought processes of other persons. At the pre-trial trial review I largely, although not entirely, upheld the Defendants’ objections. This led to a cross-application by Glaxo to exclude parts of the witness statements served by the Defendants on similar grounds, which I partly upheld. At trial, by contrast, both sides repeatedly asked questions in cross-examination which were at least arguably inadmissible without objection from the other (although the Defendants did object to certain questions which were sought to be put by Glaxo to a couple of witnesses). In assessing the evidence, I have attempted to give weight to the witnesses’ evidence of fact and not to their expressions of opinion.
The second point is that counsel for the Defendants pointed out that the witness statements of some of Glaxo’s trade witnesses contained passages which cross-examination revealed did not accurately reflect their practices. As counsel accepted, this was probably not the witnesses’ fault: they are busy people who perhaps assumed that the statements which had been drafted for them were accurate without checking this sufficiently carefully. It follows, however, that it is the oral evidence which matters.