InLaw Offs. of D’amico & Assoc., PLLC v D’Elia ; 2011 NY Slip Op 21160 ; Appellate Term, Second Department attorney (plaintiff) has sued client (defendant) for fees, while at the same time attorney (defendant) is being sued for legal malpractice in Supreme Court by Client (plaintiff.) What happens to the Civil Court fee suit when the Supreme Court malpractice is dismissed.
The general rules of civil procedure apply. While there may be application of res judicata and collateral estoppel there is also application of the rule that you may not bring up new arguments in reply.

"While plaintiff, in its initial moving papers, sought to dismiss defendant’s counterclaims pursuant to CPLR 3211 (a) (1) and CPLR 3211 (a) (7), it did not, in those papers, seek dismissal based upon res judicata pursuant to CPLR 3211 (a) (5), and it implicitly sought dismissal on res judicata grounds, if at all, only by letter to the District Court. New theories and arguments in support of a motion which do not appear in the initial moving papers should not be considered by the motion court (see e.g. Ritt v Lenox Hill Hosp., 182 AD2d 560 [1992] [reply papers should not be used to raise new arguments]). By granting plaintiff relief on the alternative ground implicitly raised by its letter, the District Court relieved plaintiff of its burden of demonstrating in its initial moving papers that the claims asserted against the D’Amico firm in the Supreme Court action were the same as those asserted against it in defendant’s counterclaims in the instant action, and deprived defendant of a meaningful opportunity to contest that issue (see Fergusson v Dumbacher, 21 Misc 3d 145[A], 2008 NY Slip Op 52547[U] [App Term, 1st Dept 2008]; Zarintash v Kopple, 5 Misc 3d 130[A], 2004 NY Slip Op 51309[U] [App Term, 1st Dept 2004]). Accordingly, it was error for the District Court to dismiss defendant’s counterclaims on the alternative ground of res judicata implicitly raised by plaintiff.

In view of the foregoing, the order is reversed, and the matter is remitted to the District Court for a new determination of the branch of plaintiff’s motion seeking to dismiss defendant’s counterclaims pursuant to CPLR 3211 (a) (1) and CPLR 3211 (a) (7). This disposition is without prejudice to plaintiff’s seeking dismissal of defendant’s counterclaims on the ground of res judicata upon proper notice. "

Plaintiff lives to fight another day, but is unlikely to win the war.