Strangely enough - this happened to me when I played (a really long time ago) and I've never forgotten it. The team was killing us 50-something to nothing and they ran this play for a touchdown on my side (I was the safety). I knew what he had done and had some words with the coach. Almost impossible to catch this as an official - but I sometimes glance at the sideline as the WH to see if any offensive players are standing with their helmets on near the end of the team box - I just note their number in my mind. Funny how something like that sticks with you for 30+ years! Hmm, maybe I should just get over it.