aside from the announcer and mom calling this a block in the back on a defensive player, since mom is trying to drag a viral hate mob on a 15-18 year old kid (expose the player, her words) for something that happened in the first 2.5 seconds of a contact football play between the whistles, why not consider it from the defensive perspective.
the play in the video is the "modern day triple option", with the three options being: give the zone, qb keep, or qb throw the bubble on the run. It's run here almost exactly as we seen frequently now in the NFL and college.
see here for a video of the play going to the third option (the bubble). the play is intended to cause the olb to bite either on the zone or qb run, opening up a lane for the bubble option, a lane which you can see at :08 timestamp.
The qb and two receivers are playing out the second and third option. i see #2 blocking #22, and in #22s line of sight until tenths of a second before the collision. you can see rockets #2 with his hands still on #22 with :08 timestamp, and the contact occurs within the :08 timestamp, the same second.
when the rockets were prepping for PND, who seems to run mostly old school triple option variation, do you think they were teaching the players to tackle their responsibility (dive qb pitch) on every play, rather than trying to figure out who had the ball? that's the way everyone i've ever heard of teaches to play triple option. every play, get the dive, the qb, and the pitch on the ground. was rochester not tackling the dive back when he didn't have the ball? again, less than 1 second elapses between the corner escaping the block and the hit.
