EPTHe could have broken the push at 6 at any time, if he had garrisoned his units into the center and used the map for a 4-5 front flanking-surround.
He could have ended 3 at any time. He never went below 2500 in the lategame. A thousand minerals of hydra/ling would have torn apart flash at any time. His play was un-professionally bad in the mid-late game.
Since it isn't likely this was a fixed match, I think he psychology fell apart with an advantage that was too large, some competitors crumble once they achieve the position of their dreams and that is the only explanation for how badly he played.
(also he didn't place any forces in positions to contest Flashes sauron expands, which in midgame TvZ are as his as his finger print.)
