Pittsburgh and its mayor are immune from the type of lawsuit that UPMC has aimed at them, according to a motion filed by the city Tuesday. Adopting the blowtorch tone of the 3-month-old court battle between the city and its biggest employer, attorney E.J. Strassburger called UPMC's legal broadsides of three weeks ago "bizarre" and "a breathtaking mix of innuendo and illogical leaps." In a motion filed for the city, he said UPMC's civil rights lawsuit against the mayor was "such an irresponsible, overwrought paroxysm of a response as to raise legitimate questions of UPMC's sincerity and purpose before this court."