I wouldn't necessarily focus on Michigan last shot. Its more than that for them. In the last 2-3 minutes in every game they seem to step up an execute in close games. Great teams do that alot. Average teams will do it every so often. That's your receipts on seperation
They worked hard to put themselves in a position to win, yes .. but actually winning on a 26-ft buzzer beater takes an element of luck that can't be ignored.
There is luck in every game... Usually it's a matter of winning by 8 instead of winning by 11, or whatever. In single possession games, luck is a much larger factor because of so many things that happen during a game that are not directly the result of actions in the player's sphere of influence.
The ball bounced in Michigan's direction 9 out of 9 times, which is unusually fortunate when looking at the scope of all basketball teams and all basketball games.
It's like flipping a coin and getting heads nine times in a row... It happens, but it's rare.