He makes some dumb decisions. He's really careless with the puck, especially in the defensive zone. He's also really careless with his sticks. If there's a puck by the opponents head, Bertuzzi can't resist the urge to whack it even when the risk-reward ratio isn't there. If he hits the puck, it's just going to likely go to the Bruins. If he misses the puck and hits the Bruin in the face, it could be a 4 minute penalty. He still swings at it no matter what.
Even in Game 3, remember that goal that was called off for Bertuzzi high sticking the puck? There was absolutely no reason to rush and hit that while it was over the bar. He just couldn't resist. It was him and Matthews both alone and Swayman didn't even know where the puck was. Matthews, the player who grew up playing baseball, was waiting for the puck to get under the bar to bat it in and Bertuzzi just sees the puck and hits it with a high stick killing a likely goal by Matthews or even him if he had the sense to wait. We got very fortunate that Tavares scored on that same PP (our only PP goal this series) and that it didn't cost us the game or this series would have been over in 4.
He makes low IQ decisions like that often. He'll start engaging players when there's no need to and honestly, I don't think he's been particularly good at getting to the front of the net. He seems to always get there too late and when he is there, he just starts banging at the puck with no purpose - he'll bang it into Swayman's pad 3 times instead of trying to go around or elevate it.
He's worth it for the right price but I don't know if he's a 5M+ player for all of his faults. If anything, I would much rather pursue Jake DeBrusk who is a UFA this offseason and requested a trade out of Boston a few seasons ago. He has the talent of Bertuzzi but a much higher hockey IQ.