i wouldn't be surprised if Harris was playing with a hurt groin all season... He does need to be back for the final division games against MIA and BUF - those could be the deciding factor in who makes the playoffs.
Well I can't be sure because I don't know what the call was - he didn't turn and start running towards the endzone until the ball was thrown though. It looked like a cover 2 defense where Elam vacated his safety spot to me.