I think Game 2 was almost the best thing that could have happened to the Leafs, aside from the impending Kadri suspension and the loss. Almost everyone has been critiquing all the penalties that weren't called, and as a result, the refs for Game 3 onward are going to call everything to avoid another Game 2 situation.
Penalties called favours the Leafs in my opinion, because the reason the Bruins run so much interference/holding/cross-checking is to control the Leafs speed. The same thing that happens to McDavid. If they're getting penalties for holding up the Leafs players, the Leafs should have an advantage as they should be quicker.
When the game is called by the book, the Leafs have the advantage. The Bruins benefit from the false pretense that 'playoff hockey' allows for you to be above the law.