If a guy's knee turns in spaghetti on a chop block, not good enough, they'll say the play was already illegal. It's going to have to be like a 1-on-1 cut block on the outside (so none of this "accidentally" falling down onto an adjacent lineman), and the DB ends up looking like his legs were screwed on backwards. Kickoff rules didn't change until Eric LeGrand nearly died, targeting didn't show up it came to light the extent to which the NFL tried to bury its concussion problem.