Both injuries are probably more accurately laid at the feet of style of play than "he has bad bones" or some such shit.
On the hit in the AHL that broke his leg, he came around the net to try to engage the play entering the corner, got hit by a defender trying to run passive interference and run into another player trying to hit him before he could get to the puck. Basically 2 hits that were obvious interference in a row, Robertson falls awkwardly with his leg underneath him and breaks his fibula. On the shoulder injury, he goes into the corner chasing a puck on a 50/50 and the defender hits him before they're anywhere near the puck, Robertson loses his balance and hits the ice hard.
Kid needs to learn that he's playing against men, and that he has to anticipate the play and be a half step early rather than, like you put it, have tunnel vision when he's on the puck or chasing it. He's too small to keep putting his nose into places where it can get broken.