Rich Products Corporation asked Kenyon & Kenyon to file applications in Mexico and Columbia. Apparently, the firm timely filed the Mexican application as of how the law was then-interpreted; but the law later changed, and the application was deemed filed too late. Rich Products then sued the firm for malpractice. The New York Supreme Court, Appellate Division, held that because malpractice is measured at the time of the events, the lawyer had breached no duty. The case is here.
This is something I often think about, given the changing nature of the “rules” about claim interpretation. For example, certain claim formats have grown less helpful over the years. I also wonder how much this defense works if it’s a foreseeable change in the law (it’s not clear here what, exactly, changed in Mexican law).
The case was remanded to figure out the Columbian claim.