TVR was guarding the crease next to Buchnevich and jostling with him yet you don't see him drive him down and punch the back of his head.
Pavel may have crossed the line there too but when the play's stopped, I don't see how it's acceptable for anyone to keep socking Strome as the third man in, then when Panarin came to support Strome he turned on him, then throw Panarin down and start hitting him. In short, Buchnevich may have started it but Wilson doesn't get to keep going and escalating it as he pleases just because he's the toughest out there.