Plaintiff must always prove that departures from good and accepted practice by the defendant were a proximate cause of the injury. Note that there need be no proof that the departure was the proximate cause. In Arbor Realty Funding, LLC v Herrick, Feinstein LLP 2013 NY Slip Op 01216
Appellate Division, First Department we see such an application.
"Defendant argues that even if, but for its allegedly erroneous legal advice as to zoning issues, plaintiff would not have made bridge loans to the developer of a residential tower at 303 East 51st Street in Manhattan, plaintiff cannot establish legal malpractice or negligent representation because it cannot demonstrate that the zoning advice proximately caused its loss on the defaulted loans. Plaintiff made the loans in mid-2007. Defendant contends that the crane collapse at the project site in March 2008, which killed seven people, the market collapse beginning in late 2007 and continuing through 2008, and plaintiff’s insufficient response to the Department of Buildings letter notifying plaintiff of its intent to revoke the project’s building permits, constituted intervening events that severed the causal link between defendant’s zoning advice and plaintiff’s loss (see Derdiarian v Felix Contr. Corp., 51 NY2d 308 [1980]).

There is, however, evidence in the record that raises an issue of fact as to causation (see Brooks v Lewin, 21 AD3d 731, 734 [1st Dept 2005], lv denied 6 NY3d 713 [2006]). It appears [*2]that potential takeout lenders had concerns about the zoning issues even before March 2008. To the extent later events contributed to plaintiff’s loss, they are properly considered by a fact-finder (see e.g. Schauer v Joyce, 54 NY2d 1 [1981])."