Boston Scientific v Edwards: Witness cross-examination

The issue arose out of the rule of evidence that, if a party wants to submit to the court that a witness’ evidence on a point should not be accepted, the witness should be challenged on that point in cross-examination.

In the case at hand the defendant to the patent infringement action, Edwards Lifesciences, did not cross-examine one of the patentee’s, Boston Scientific Scimed, expert witnesses on the prior art. The Patents Court subsequently held that one of the patents was invalid for obviousness (the other patent being held to be valid and infringed).

Both parties appealed, Boston Scientific Scimed arguing, among other things, that the trial judge erred in his conclusions on obviousness in the absence of such cross-examination. The Court of Appeal acknowledged the rule of evidence, but noted that it was not inflexible. It emphasised that (as is common with English patent litigation), multiple expert reports (in chief and reply) had been exchanged. The issues in the case had, therefore, been defined and the expert was apprised of these. Further, in its view, there was some overlap between Boston Scientific Scimed’s expert witnesses’ evidence. It did, however, encourage practitioners who did not wish to cross-examine a witness (for example, to save time and cost) to raise this issue in advance with the other side and the court so any issues could be raised and directions given.

The Court of Appeal upheld the first instance decision.