Goff said it was a bad call and I agree. But perhaps a more experienced receiver than rookie TeSlaa would have, once bumped by the one Steeler defender, quickly turned his face towards Goff as if he was expecting a pass, maybe even thrown his hands up. He does that and I don't think the flag is thrown. Looking at the replay, it looks like ASB saw the flag - with the flag being out of sight of the TV viewer - a second or two after catching the ball, just as he was beginning his TD celebration. So I wish CBS hadn't teased us by waiting 12 seconds to tell us there was a flag.