Other players did, but Pare refused to fight.
For Arber refusing wasn't an option. Most players won't go up and sucker punch a guy unless you're Max Domi. Xhekaj was incensed and went after him. Guy turtled.
Nobody tried to fight Paré before Arber did, and somebody clearly had to. Andy had two golden opportunities on both the shift of the injury and the shift where arber got a hold of him, he did nothing but skate soullessly around the ice. Nobody had to 'sucker punch', which isn't even what happened when Arber fought. Anybody could have just jumped on him and thrown him around a bit and drawn coinciding 5s and an extra 2. That's a team toughness/ coaching awareness problem.
The point I'm making is that Marty could and should have avoided losing another D so early if he had just opened his eyes for a second. Maybe his system is too confusing for lame brains like Andy, the nascar driver of hockey players, who can't juggle turning left and realizing some plug just ripped up your best forward's knee.