A lot of walk-off wins involve fast running and close plays. The only "true" walk-offs are game-ending homers. (I guess a ground-rule double with a man on second would count.) Or game-ending bases-loaded events, like a walk, HBP, catcher's interference, pitch-clock violation, etc. Otherwise they are really not "walk" offs where the winning run can literally walk home. All of that to say the Giants had a true walk-off with Wilmer Flores getting walked with the bases loaded in the 9th to win the game.
So, miracles do happen.