OK, he didn't really cost the Patriots a chance at winning. The Patriots did that by themselves. However, Polamalu did make an illegal play at the end of the game when he slapped the ball towards the Patriots endzone, resulting in a safety.
Polamalu was asked about the play after the game, to which he said, "Whatever is going to get me in trouble, I'm saying the opposite." Polamalu had five tackles in the Steelers' win on Sunday.