I don't know what the fed rule says specifically, but under NCAA, I've got an illegal block. Key def out of Rule 2: "...the force of the initial contact is from behind..." That's met here.

Watch it again. He's clearly a yard (at least) behind him. Closer to the sideline by 6-8 inches to be sure, but easily behind him. But I can't comment on the Fed rule.

That's interesting. Before the 2002 NFHS rule change this would have been a clip (there was no block in the back). I believe the NFHS sought specificity on the rule and in effect gave blockers some additional latitude and officials a more concrete definition.

I know what the rule says, and in my opinion, there is contact here that meets the rulebook definition of a BIB.

I usually give the blocker a good amount of lattitude. If it is a block from the side or shoulder, I have nothing. But in this one, most of the contact looks to be in the back.