What happens when the Defendant-Attorney defends itself, and the main witness plaintiff seeks to call is that attorney?  The textbook answer is disqualification on the advocate-witness rule.  That’s exactly what happened in Lauder v Goldhamer  2014 NY Slip Op 08321  Decided on November 26, 2014  Appellate Division, Second Department. 

"The disqualification of an attorney is a matter that rests within the sound discretion of the Supreme Court (see Nationscredit Fin. Servs. Corp. v Turcios, 41 AD3d 802, 802). Here, the Supreme Court did not improvidently exercise its discretion in granting that branch of the plaintiff’s cross motion which was to disqualify Kantrowitz from representing the defendants pursuant to the advocate-witness rules (see Rules of Professional Conduct [22 NYCRR 1200.0] rule 3.7). The allegations in the amended complaint and the plaintiff’s affidavit established that the testimony of Kantrowitz, who was the only attorney involved in the plaintiff’s execution of the retainer agreement and who the plaintiff alleged made certain misrepresentations that induced her to execute the agreement, would be necessary to resolve issues pertinent to the cause of action to set aside the retainer agreement (see Fuller v Collins, 114 AD3d 827; Falk v Gallo, 73 AD3d 685).

Accordingly, the Supreme Court properly denied those branches of the defendants’ motion pursuant to CPLR 3211(a)(7) which were to dismiss the amended complaint insofar as asserted against the defendant Paul B. Goldhamer individually, and to dismiss the second, sixth, and seventh causes of action, and properly granted the plaintiffs’ cross motion."