Doctors and lawyers, legal and medical malpractice.  The two fields of law have many similarities, and in this case they are all mixed up.  Doctor hires attorney to handle a purchase of a Co-op for use as a medical office.  It turns out that there is no certificate of occupancy for use as a medical office.  Doctor closes anyway and then pays significant sums to amend the c/o.  Doctor sues attorney.  Doctor loses at trial.

Sarah Stackpole, M.D. v Cohen, Ehrlich & Frankel, LLP ; 2011 NY Slip Op 02137 ; Decided on March 24, 2011 ; Appellate Division, First Department  illustrates the "but for" element of legal malpractice.  Sure, you might prove that the attorney did not advise you about the lack of c/o.  Sure you might prove that it costs a bundle to fix the problem.  Sure, you might prove that it would be a departure not to advise you.  But, can you prove that you would not have bought the co-op anyway?  Here, the doctor could not.  She lost.
 

"The record supports the trial court’s finding, based on credibility determinations, that plaintiff failed to prove that defendant did not advise her that her intended use of the apartment was impermissible under the certificate of occupancy (see Garza v 508 W. 112th St., Inc., 71 AD3d 567 [2010]). To the extent that defendant was negligent in failing to further advise plaintiff of the consequences of occupying a cooperative apartment in contravention of the certificate of occupancy, plaintiff failed to prove that, but for defendant’s negligence, she would not have purchased the apartment. To the contrary, plaintiff testified that she had been made aware of the "horrors" (including the cost) of amending a certificate of occupancy several years before in connection with an apartment in another building; despite this awareness, she purchased the subject apartment (see e.g. AmBase Corp. v Davis Polk & Wardwell, 8 NY3d 428, 435-436 [2007]; Orchard Motorcycle Distribs., Inc. v Morrison Cohen Singer & Weinstein, LLP, 49 AD3d 292 [2008])."