I will admit I was wrong about one thing. The crown did hit, I hadn't seen a good angle of the replay. Doesn't change anything else about what I said though. "Leading" means he intentionally lowered his head and lead with his helmet. Watch the freaking replay and take off your blinders. He lowered his shoulder to make a tackle, now I might be mistaken, but I'm fairly certain the head is attached to the shoulders, so the head followed. When he lowered his shoulder to make the tackle, Lawrence was standing at full height. All things being the same from that point, his shoulder hits Lawrence in the torso. Instead, Lawrence started to duck when he saw the hit coming, causing the helmets to hit. It most certainly does matter, because it's the difference between intent to do something wrong, and incidental contact because of the way Lawrence moved.