Parkinson v Guidant Corp

2004 WL 837858 (W.D. Pa. 3/22/2004)

An attempt to exclude expert testmonies


This was an American case concerning a faulty guidewire used during surgery. The plaintiff put forward a number of experts on issues in the case and the defendant sought to exclude their testimonies. The first was a physician, Dr Moy, whose discipline was interventional cardiology. His opinion went to causation, in that his evidence would be that the faulty guidewire had caused the plaintiff’s subsequent surgeries.

The defendant’s motion also challenged the evidence of Mr Crooks, a metallurgist, whose evidence was based on destructive testing of the guidewire in question, and that of Mr Johansen, a mechanical engineer, based on the same methodology.


The defendant claimed that in respect of Dr Moy, his failure to rule out alternative causes for the plaintiffs’ subsequent surgeries, and the fact that his opinion was not based on a valid temporal relationship, meant that his testimony was inadmissible.

In respect of Messrs Crooks and Johansen, the defendant argued that Mr Crooks was not suitably qualified, his opinion and methodology were unreliable, and that he could not say whether the alleged flaw caused or contributed to the injuries sustained. Similar arguments were made in respect of Mr Johansen’s opinion and methodology.


The court admitted all three expert opinions, noting the ‘liberal standard for admissibility’. In respect of Mr Crooks, he was amply qualified in that he had more than 30 years of experience in the production of wires. In respect of methodology, the court found all three experts’ opinions were based on sufficient facts and data, and were reliable. The arguments put forward by the defendant were properly matters going to weight and credibility, not to admissibility.


This approach is very similar to that which would be likely to be adopted by the English courts.