Maybe I missed something but are you talking about the play on the sideline?? Dax had a very slightly late hit on the QB running for yardage. Ok fair enough. (Sidenote the moron announcer's comment that its was only a late hit because it was a QB and not a running back was one of the dumbest things they said all night and thats a high standard)
Anyway so Dax is going full tilt. He makes the late hit and the BC coach see it and reacts by running into the white area to get in Dax face. Same Dax thats playing the game and running full steam. Coaches in the white area are not allowed and that is supposed to be a penalty. Can't really blame Dax or any player for all the sudden having some jackass jumping in their face from the sideline. Its not like he has time to analyze oh this is the head coach. I wish Dax would have flattened him. Thats what the dude gets for jumping in a running players face in the white zone and thats why the rule is in place
Note this is not about being a Dax fan boy. I think his play is subpar and he is not a P5 linebacker