I put to together a post with links and quotes and everything. But it took me so long to do it I got signed out and lost it...grrr. The distinction is between fact "testimony" and opinion or expert opinion "testimony" -- not between fact and opinion. Neither conclusively establishes a single thing as fact, but the rules that apply to each type of testimony are quite different. There is absolutely no question in my mind that the order of the assaults has not been conclusively established
here's a snip and link from a case talking about fact and expert testimony given by an investigator in a criminal case w/ bbm. In one of my snips below, note the use of the term "mere fact witness." There's a reason for that.
Undue Weight:
The jury might be smitten by an expert's aura of special reliability and therefore give his factual testimony undue weight. York, 572 F.3d at 425 citing United States v. Brown, 7 F.3d 648, 655 (7th Cir. 1993) ([W]e recognize that in a close case the danger of unfair prejudice may be heightened by the aura of special reliability that often surrounds expert testimony, and that jurors may tend to give such testimony undue weight. The danger of unfair prejudice is most serious where the expert also is an occurrence witness.) (citation omitted)
http://federalevidence.com/blog/200...ng-dual-fact-law-enforcement-expert-testimony
And here's a snip and an article (bbm) talking about the distinction in the context of medical professional witnesses:
One of the vexatious problems that plague trial lawyers is dealing with experts, particularly medical experts. The generic term expert, according to the American Heritage Dictionary, describes any person with a high degree of skill or knowledge of a certain subject.
There are, however, expert persons who are mere fact witnesses in a particular lawsuit. These individuals are variably called fact experts, occurrence experts, actor experts, viewer experts or non-26(b)(5) experts.
* * *
But many experts possess facts or knowledge independent of the lawsuit and are also asked to express opinions at trial, often based on those facts. The best example of this hybrid expert/fact witness, of course, is a physician who has treated the plaintiff for his or her injuries.
The status of a particular expert will determine whether he is a mere fact witness, an expert person, an expert witness, or some combination thereof. The status of an expert in a particular lawsuit will then determine whether the lawyer must pay the expert merely a statutory witness fee or an expert witness fee; whether a party who did not hire the expert can depose the expert; whether the experts records or opinions are discoverable; whether the expert needs to be disclosed to the other side; and whether an expert person who is a fact witness must answer expert questions at a deposition or trial.
The test for whether a witness is an expert or fact witness is whether the facts or opinions possessed by the expert were obtained for the specific purpose of preparing for litigation. Peters v. Ballard, 58 Wn. App. 921, 795 P.2d 1158 (1990).
http://www.pereylaw.com/articles-videos/issues-in-working-with-medical-witnesses/
