Terrible penalty, but I can’t see block in the back being a previous spot foul at the NFL level. I would have to research rulebook references. But I know the Bills could have declined the offside. That would negate the double foul and, thus, the offset. Then the block in the back would have been enforced, which I believe is a spot foul. That run looked to be a 20 yard gain, so I think it would have resulted in around 1st and 5? Maybe 1st and 10. Depending on spots.