[Under New Jersey law] a required element of the causation proof [of legal malpractice by patent counsel] is for the plaintiff to demonstrate that the invention would have been patentable.

On May 4, 2012, in Minkin v. Gibbons P.C., the U.S. Court of Appeals for the Federal Circuit (Rader, Dyk,* Moore) affirmed the district court's summary judgment that Gibbons did not engage in legal malpractice in prosecuting the application that issued as U.S. Patent No. 6,012,363, which related to a hand tool called extended reach pliers (ERP). The Federal Circuit stated:

[We have] jurisdiction in patent attorney malpractice cases such as this one, in which the plaintiff is required to establish that, but for attorney negligence, he would have obtained valid claims of sufficient scope that competitors could not easily avoid.... The crux of Minkin's allegations is that Gibbons negligently drafted patent claims overly narrow in scope, constituting legal malpractice. Because state law creates Minkin's cause of action for legal malpractice, this court must apply the law of New Jersey to decide whether Gibbons is liable. To establish legal malpractice in New Jersey, a variation on the tort of negligence, a plaintiff must demonstrate in its case-in-chief: (1) the existence of an attorney-client relationship imposing a duty of care upon the attorney; (2) breach of that duty, defined as deviation from the standard of care; (3) proximate causation; and (4) damages. This case hinges on the third prong, that is, whether Gibbons's actions proximately caused the loss to Minkin.

New Jersey law provides several ways of establishing proximate causation in malpractice cases, including a "suit-within-a-suit." The suit-within-a-suit approach applies where recovery depends on success in the underlying matter and "aims to clarify what would have taken place but for the attorney's malpractice." New Jersey trial courts commonly employ this approach where the parties agree to that process. There can be no causation demonstrated under the suit-within-a-suit rubric for patent prosecution malpractice where any claim drawn to the alleged invention would have lacked patentability ab initio. Thus, a required element of the causation proof is for the plaintiff to demonstrate that the invention would have been patentable. Malpractice suits in a patent prosecution context most frequently arise where attorney negligence results in a final PTO rejection. Here, Minkin complains not that a patent did not issue, but that the allowed claims were drafted too narrowly to protect the ERP against competitors, namely Danaher. Because the parties agree that the "suit-within-a-suit" analysis applies, Minkin must prove by preponderant evidence that alternate claim language would have been deemed patentable by the PTO and that it would have read on the Danaher tool....

In granting summary judgment, the district court held that Minkin failed to raise a genuine dispute of material fact regarding patentability. Specifically, Minkin provided no evidence showing that [two alternate claims for the Minkin ERP proposed by Minkin's expert Richard Gearhart] would have overcome an obviousness rejection at the PTO.... In its motion for summary judgment, Gibbons identified § 103(a) issues with respect to the alternate claims, submitting expert opinion questioning Minkin's ability to obtain even broader scope in light of the record. Because it was Minkin's ultimate burden at trial to establish nonobviousness, it bore the burden on summary judgment of demonstrating a disputed material fact regarding this essential element of its case, especially given that Gibbons put § 103(a) directly at issue.

Minkin defends that it would have been too cumbersome in the first instance to "prove a negative" by addressing every potential combination of prior art that could be used in an obviousness rejection. Minkin suggests that merely distinguishing each prior art reference individually was sufficient to defeat summary judgment, reflecting actual practice before the PTO where applicants often await an examiner's specific § 103(a) rejections before discussing nonobviousness. We recognize that applicants do not typically prove "validity" against all prior art, and only show that claims are not invalid over references cited against them. But the order of typical prosecution practice is irrelevant to the procedural posture here. Malpractice cases under a suit-within-a-suit framework require as part of the plaintiff's case-in-chief a demonstration of the likelihood of patentability. In the context of summary judgment, we hold that the district court was obligated to determine whether Minkin could satisfy its ultimate burden of showing patentability in light of Gibbons's motion....

The challenge for Gibbons all along, as noted by the district court, was drafting broadly in the face of such a crowded art field. Including a 3:1 pivot ratio limitation was the final compromise to the claim language agreed on by the examiner and inventor in an effort to secure patentability. The language of the issued '363 patent, however, is entirely distinct from the alternate claim language drafted by Gearhart, who attempts to capture more scope for purposes of this litigation. An inference of nonobviousness does not attach to the alternate claims by virtue of the issued '363 patent because the claim terms are different. The fact that the ERP was ultimately deemed nonobvious after handling a prototype does not mean that an examiner would necessarily decide the same thing if the claims were broader. We therefore refuse to conclude that an examiner would have allowed Gearhart's alternate claims of greater scope just because the more narrow '363 patent issued after an in-person interview.