What is the defender to do? Anticipate that a guy is going to intentionally fall forward into him??

It is kind of like “targeting” penalties where the defender tries to turn his helmet away from contact but then the other player changes direction and it ends up being a direct hit (and this “targeting”). I’m not suggesting that football players are trying to induce targeting the way basketball players are trying to induce a “foul” on a three point try, just saying in both cases the defender is screwed and at the mercy of the ref.