Aileen ( and others), you really should let this go. Andy won, Novak lost. Yes, things might have turned out different in many ways for either player, but Andy won in straight sets in a very intense and exciting game. We should rejoice, and stop second-guessing alternative scenarios.
With most people I reckon it's due to stress, and there was no shortage of it in that match. First there's the huge feeling of relief, then the 'what if' anxieties start to creep in. It wouldn't surprise me if Andy plays that last game over and over in his mind for a little while once things start to settle down.
That last game I was begging for an ace.
Me too. After it went from 40-0 to deuce I was rooted to the spot, and Andy said later that he started to feel panicky then because he didn't think he had much left in the tank mentally, so hats off to him for keeping his nerve while we were losing ours - but then again desperation can often work wonders.