If the flu is as bad as it's been hinted at (e.g. Keefe spending the last few games talking about "game time decisions" for the roster), it's showing: by the time they got to the back half of the third, they were dragging. Against a potent Toronto forward corps, that's death.
That gives me some hope, at least; all season before this stretch you were able to tell the Devils were a cut above the also-rans of the league because they could skate hard for sixty minutes, while you'd be able to tell which teams just couldn't keep the pace going the full hour. They didn't suddenly forget how to do that, so it tells me the sicknesses around the room are probably taking their toll.
The part that sucks is that they had that shitty, shitty road trip before this, though, when they choked instead of feasting on teams like Anaheim and San Jose. It's just made this whole stretch since Christmas...well, not miserable, they've played plenty of strong games in that time, but the inconsistency and the general fan-PTSD of the last decade-plus has left us all just waiting to be hurt again.