A legal malpractice action can be dismissed where the client cannot prove that damages occurred due to the attorney’s malpractice (what is commonly referred to as “but-for”). In Lisi v Lowenstein Sandler LLP, 2019 NY Slip Op 01665 [1st Dept Mar. 7, 2019], the court held:
In this legal malpractice action, plaintiff alleges that defendants were negligent in failing to advise him that the income realized from the exercise of his stock options would be taxed as ordinary income and that, had they so advised him, he would have sold his shares earlier or eliminated any market risk by shorting the shares in full or otherwise taking measures to eliminate risk. However, this theory of proximate cause is belied by the record and relies on gross speculation (see Gallet, Dreyer & Berkey, LLP v. Basile, 141 A.D.3d 405, 35 N.Y.S.3d 56 [1st Dept. 2016]; Sherwood Group v. Dornbush, Mensch, Mandelstam & Silverman, 191 A.D.2d 292, 294, 594 N.Y.S.2d 766 [1st Dept. 1993] ).