The plaintiffs clearly thought that by putting an MD on the stand who would agree with their case, that would be sufficient. Perhaps they felt a jury would be sympathetic to their case, if the decision came down to a proverbial "battle of witnesses." However, in this case there was no such battle. Dr. Miller was not an expert and while his testimony was not excluded on those grounds, it could have been. Nonetheless, his lack of expertise showed through in his faulty methodology. This hints at another point of significant from this case regarding expert testimony. While Dr. Miller could have been excluded on Rule 702, since he was clearly not an expert, the district court did not use this as grounds for excluding his testimony. This sent a signal that courts should give the expert witness the benefit of the doubt with respect to marginal qualifications. If the witness is indeed no expert, this will be revealed by the faulty methodology they use, which will allow for exclusion under Rule 703.

The dissenting judges felt that the majority was amending the Rules of Evidence. One dissenter when so far as to state that "a dispute among qualified experts would preclude, not mandate, summary judgment." The dissenting judges fail to recognize that not every person put before a court as an "expert" is one, nor should their opinions be allowed if they are not based on methodologies...

If there is any such amendment to the Rules of Evidence in Christophersen v. Allied-Signal, the amendment is to strengthen the rules, making them less open to abuse from fraudulent "experts" who testimony is geared more towards engendering sympathy from a jury.
Despite the objections, Christophersen v Allied-Signal resulted in expert testimony being forced into a higher standard. It was no longer acceptable to trot out the Dr. Millers of the world. Instead, experts not only required ample qualifications, but they needed to conduct themselves as an expert would, in order for their testimony to be entered into trial. By strengthening the standards for expert opinions, Christophersen v Allied-Signal strengthens the integrity of the court system. The ruling still left many areas open for interpretation, however. For example, it was not determined precisely what constituted expert methodology, opening that realm up for dispute among experts. The appropriateness of different methodologies was thus not covered in the decision (Faulk, 1992).

Works Cited:

Christophersen v. Allied-Signal Corporation. Retrieved April 12, 2009 from http://altlaw.org/v1/cases/518069

Faulk, Richard O. (1992). The Unanswered Questions of Christophersen v Allied-Signal Corporation. Villanova Environmental Law Journal. Vol. 4.1 pp 21-39.