Collins had decided to pull Harvey after 8 IP, but Harvey talked him into letting him start the 9th. Good ol' Harold Reynolds said Collins "had no choice" but to let Harvey start the 9th inning. Harvey gives up a walk and a double to the only batters he faced in the 9th. Familia gets two ground outs, but Royals tie the game in the process when Duda throws the ball away while Hosmer scores tying run. A good throw would have had Hosmer out by several steps.
So Harvey's macho personality and Collins' willingness to give in to it (along with poor defense) probably cost Harvey the win, and may enable the Royals to finish off the Mets to win the World Series.