What I feel was the Hawks reason for winning was Coaching.
Joel Quenville, After he saw his 1st line had only recorded 1 point in 3 games, between the 3, broke up the line, Putting Towes with Hossa, which turned out well, Byfulgeon on the 3rd line, and kept Kane with Sharp on the 1st. Look who scored the tying goal, and the game winner, Sharp and Kane.
Peter Laviolette I feel didn't change enough after both of the embarrising losses, keeping Carter and Richards together the whole series, 1 goal from both is pathetic from such elite players as them. And Goaltending.... If Laviolette actually thought he could win with Leighton after the 1st away loss, why did he continue to play him.. I know Flyers fans who even thought Leighton shouldnt have started after game 1.
The teams were very even, it all came down to matchups and coaching.