It's a mystery that I can't figure out, hockey is a high intensity, high speed and highly emotional game, collisions happen as a matter of course. From the time you enter any kind of "rep" hockey, physical intimidation becomes as big a tactic as running a flawless breakout or PK. While there is a certain lack of physicality in todays game because of rule changes and league policy("Gary Bettmans' Americans don't like fighting" mantra). I really have no idea how or why you'd pull in the horns when the opponent is hammering you all over the ice, but the Leafs seem to do it and other teams seemingly don't. I am not talking about "throwin 'em" and becoming todays version of the Philthy Flyers, I'm talking about playing tough physical hockey, using the boards as a separator, open ice hits when the opportunity presents itself, a hard forecheck, and "protecting" the crease, but they just don't.
The only logical conclusion is that the team mandates they play it close to the vest and avoid the physical side of the game as much as possible. That thing with Hyman, if it had been me playing, the next opportunity that came up to crush Hughes or Tanev would've been taken, screw the roughing/boarding call.