We can debate all day (and some will) whether or not Jack Johnson should have been removed from the lineup and replaced by Olli Maatta.
We should actually be discussing whether or not it was the right move to put Dumoulin on the ice for game one. Dumo is a stud. He's one of the best defensive defensemen in the NHL. He didn't look like himself last night.
The question can be asked...If this were December, would he even have played? Dumoulin was lost on the first goal, not being able to get to Jordan Eberle quick enough. On the second goal Dumoulin was, again, slow getting to Brock Nelson. On the game winner, Dumo lost his balance and wound up on the ice.
He hasn't made three mistakes like that in a month let alone one game.
He's clearly not 100 percent. Should Mike Sullivan have given him an extra day or two?
The argument to the contrary is: You'll need Dumoulin to play and play well at some point, so why not put him on the ice for game one and see if he can get his footing?
Maybe it works out that Dumoulin gets better as the series goes along and the Penguins find a way to win. Whether he should have player or not, though, is a conversation worth having.