^The worst thing about that play was that he got tackled. If anyone from the other team was paying attention, they would have gotten a safety out of that. Still, I've never seen that before.
Technically, it was blown dead because you can't advance the ball on a muffed punt (I guess "advancing the ball" includes running it 90 yards in the wrong direction), so they wouldn't have gotten a safety. However, I can still see the instinct of "we should tackle him because maybe he knows something we don't." It's still strange that both sides can suddenly forget why they got on the field and start responding to the opposite of what's happening.