There was a lot of controversy surrounding an apparent Michigan Tech goal in the first period that was called no goal on the ice and never reviewed. It was weird because nobody reacted like it went in.
If you watch the overhead shot on the replay, it looks clear as day like it went in. If you watch the on-the-ice view, it looks clear as day like it hits the top of the net and pops up. Another possibility is that the puck actually went in the net, off the back bar and through the netting.
Hard to say what actually happened, but it turned out not to matter.