Highland Capital Mgmt., LP v. Schneider, 2008 U.S. Dist. LEXIS 7019 (S.D.N.Y. Jan. 28, 2008):

1. No Testimony as to Witness Credibility. “[Expert] Duval's opinion as to the credibility of witnesses is inadmissible.... [T]he credibility of witnesses is exclusively for the determination of the jury.... Such subjective review of the evidence is improper, and Duval does not have "personal knowledge of the underlying facts." (Citation and quotation omitted.) [Note that this rule of preclusion applies equally to non-expert witnesses.]

2. No Narrative. “[Expert] Duval's factual narrative of events giving rise to this action is inadmissible. Duval has no personal knowledge of these facts and they are lay matters that the jury is capable of understanding and deciding without Duval's testimony.” [This one could go either way. Narratives of this sort are permissible within the discretion of the Court under Fed.R.Evid. 611(a) — before even approaching the issue of summary witnesses or exhibits.]

3. No Ultimate Legal Conclusions — but Testimony as to Salient Factors Permitted. “[Expert] Duval also cannot testify as to ultimate legal conclusions. ‘[A]lthough an expert may opine on an issue of fact within the jury's province, he may not give testimony stating ultimate legal conclusions based on those facts.’ Duval, therefore, cannot state that he knows that [Defendant] Leonard Schneider or Rauch had authority to bind the Schneiders, or that there was a binding agreement. ‘Even if his testimony is couched in terms of industry practices, the expert still may not, under any circumstances, opine on the ultimate legal issue in the case.’ .... Duval can, however, based upon his experience, point to factors indicating to him that Leonard Schneider or Rauch had authority to bind the Schneiders or that there was an agreement.... Duval's testimony will likely prove helpful in allowing the trier of fact to better understand the evidence and providing the trier of fact with the tools necessary to make an ultimate determination.” (Citations omitted.)

Note the exclusion of the ultimate legal conclusion, even though Fed.R.Evid. 704 provides that "testimony in the form of an opinion or an inference otherwise admissible is not objectionable because it embraces an ultimate issue to be decided by the trier of fact." “Under Rule 704(a), an expert witness may testify to the ultimate issue of fact in the case, but such opinions may not be 'phrased in terms of inadequately explored legal criteria" (citing and quoting Media Sport & Arts v. Kinney Shoe Corp., No. 95 Civ. 3901, 1999 WL 945354, at *1, 1999 U.S. Dist LEXIS 16035, at *3 (S.D.N.Y. Oct. 16, 1999) (Leisure, J.) (quoting Fed. R. Evid. 704(a), advisor committee's notes)).

4. No New Opinions Not Contained in Expert Report. Pursuant to Rule 37(c)(1), the Court barred a new opinion — one not contained in the expert’s Rule 26(a)(2)(B) report but which first appeared in a declaration submitted after the close of discovery. The “Declaration was filed after discovery was closed, therefore, the Schneiders would be prejudiced and a continuance would have been impractical.”