SAN FRANCISCO — Just when it appeared he’d escaped, patent lawyer Raymond Niro Sr. and his firm have been dragged back into a multimillion-dollar attorney fee battle over a client’s inequitable conduct. Both the price tag and the war of words have been escalating.

U.S. District Judge William Hart of the Northern District of Illinois turned down HTC Corp.’s bid for “exceptional case” fees against Niro, Haller & Niro on June 12 after the client, Daniel Henderson, stipulated to exceptionality. That decision threw a wrench into HTC’s plans to “carry our scalp away,” Niro said at the time.