The bank calling it in put him in that position. She would be gone without incident otherwise. The cop was actually doing his duty and when she got frustrated and said he must have problems he changed his demeanor toward her immediately. Cops see the worst of humanity most of their days so don't be surprised when they react quickly and aggressively to any insults. The blame falls on the bank in my opinion. Imagine an older boy telling two younger boys lies just to watch them fight, same thing here.