Slafkovsky tried to, but he's not a dman and missed the play at the blue line. It's a mistake by Slaf, but the root cause was Hutson getting trapped deep and then breaking out the Pens.
Hutson also dogged it a bit on the backcheck, as you can see from the reverse angle:
PIT@MTL: Letang increases Penguins' lead in 3rd period
www.nhl.com
If he puts his head down and keeps skating there's a chance he can make a diving play to break up the pass.
I'm a fan of the kid, but he's going to make mistakes like this. I almost don't hate what he did here, trying to force offense late in a game down a goal, but he just got a bit overzealous.
I generally agree with your take. Hutson had quite a few mistakes, misplays, and blown coverages against the Pens. He had amazing moments too, but I'd say that this game was, even moreso than Toronto's game, the worst one of his admittedly very young career.
On another goal besides the one you talked about Anderson misread a forechecker's position on the corners when Hutson cleanly gave him the puck and he wasn't expecting it so soon. Anderson panicked a bit, as he is prone to do whenever he is tightly checked, floated the puck back/got it deviated to Hutson who then flailed at it unsuccessfully only to then have trouble boxing-out an opposing forward since he didn't have either leverage or body position in his advantage.
On that same play said forward beat Hutson clean along the boards and then made a nice pass to an open forward in front of the net who one-shot it towards Montembeault's crease for a quick goal.
Now, there were a lot of mistakes made in that sequence that started with Josh Anderson coughing-up a weird floating puck back to his D, Hutson failing in his coverage, and then Savard, Hutson's D partner, also being at fault on that play by not getting close enough to the Pens' eventual goalscorer, nor tying-up his stick.
But that one sequence I've lengthily described was not a lone play this past game for Hutson. He again made a lot of incredibly positive plays out there, but I'd say that in this particular game of his he got punished a lot for his bad plays/inability to break the cycle and that the "bad" outweighed the positives he brings on this one night.
Which is par for the course for a rookie with less than 10 games of NHL experience and who is far from a finished product on the ice, especially so for a defenseman that will only turn 21 in February of next year. Nobody is 100% polished defensively from the get-go, it takes years and many mistakes even for the very best prospects to get there. And a lot of those never even do.
Keeping as level-headed of an opinion as possible, I'd say that overall, as far as Hutson's season has been going thus far, the good majorly outweigh the bad.
But last night was a little bit tilted in the opposite direction, and we'll have to learn to live with those nights untill Hutson has at least another couple of YEARS of experience with the pros, when/if Hutson irons-out a majority of his defensive kinks and starts to play a more polished game defensively.