Blocking a defensive player on the ground

[jTheUmp]

(If A4 is an offensive tackle, you've probably got an illegal numbering foul, but I'll assume for the purposes of discussion that he was actually wearing a legal number)

Based on your description, no foul was committed by A. B60 committed a personal foul, and a potentially flagrant one at that, depending on the severity of the action. Again, based on your description, I'd be leaning towards flagrant.

Why it wasn't flagged on the field is anyone's guess. In a 4- or 5- person crew, it's possible that none of the officials saw it happen, depending on what else was going on at the time (QB being hit just after the throw drawing R's attention, umpire having to turn on a throw over the middle, etc).

Couldn't care less about how Team B feels about the situation, personally.