I believe he is afraid.He really only starts pushing/pulling ,lite jabs or a face wash when the linesmen and refs are in between.You can see it in his expression just when a conflict starts. His natural born hockey gifts of speed, size, a really good shot and when he does deliver that hit, its bone crushing. His natural talents if he chooses to use them consistently(which he should) is always gonna attract physical attention in a retalitory way. Teach the kid to fight,build his confidence. Train him with fighters of his build on how to control opponents,pick his spots ect..I'm not saying "make jake an enforcer" but teach him these tools. All Confidence based. You can see the difference in a secure man compared to an insecure one.