To date, the most common arguments for expert bias arise out of the expert’s relationship with the retaining party and the expert’s failure to consider all of the material facts and/or provide unsubstantiated opinions.
In Amertek Inc. v. Canadian Commercial Corp, the plaintiff successfully argued that an expert’s relationship with the defendant was enough to establish a lack of independence. In Amertek, the defendant’s expert had been legal counsel for the defendant in 14 U.S. cases. He testified that he saw this party as a valuable client and saw it as a source for future work referrals. Based on these facts, Justice O’Driscoll gave little weight to the defendant’s expert testimony.