I just hope he didn't recognize that the call was coming so he didn't pay any attention. I could stomach that, but knowing it's coming and not giving the puck up...
To defend Barzal slightly, I think it depends on the situation. Sure, typically you see teams give the puck up right away to get a longer 5on3, but I think a smarter play is for the puck carrier to evaluate his options and see whether there's a guy wide open he can pass to since the opposition might also assume you're just going to hand them the puck and they get lax in coverage.
I actually remember the Pens scoring on Montreal on a similar play. Pens were already on the PP, I believe, then Montreal took another one. Montreal took for granted that the Pens would let up and just hand them the puck, but instead Crosby lifted the stick of a defender, grabbed the puck and quickly sent it to Malkin, who then quickly zipped a cross ice pass to Hornqvist to one-time it in, all because Montreal kind of let up when they saw it was about to be a 5on3.
I can't recall the play perfectly, so maybe it didn't apply. If Barzal just decided to circle around the perimeter for 5 seconds instead of handing it straight to a Lightning player, then yes, that was bad. But if he held onto it for a bit longer to see if there was a golden opportunity to score, I don't think you can fault him.