1
1) Maniger had to cover a LOT of ground to have any chance at all on that ball.
2) The ball was slicing away from him and knuckling hard
3) He somehow managed to very slightly outrun it
4) if his glove were 1 or 2 inche sfurther up or back relative to his head, he makes that catch and the Mariners win the game.
That's not a "flubbed catch"...that's an "almost great play".