Actually Marty's bullet flies into a storage unit where it strikes against a suit of armor, goes through an autographed sketch of Gandalf the Grey (very intentionally placed next to an autographed picture of Sir Ian McKellen), hitting an Indiana Jones pinball machine, bouncing off against a concrete wall rolling out of his hat. Effectively the same result, but with that added bit of flavor

Marty might not be going anywhere, even if Elio's grip, previously mentioned but never confirmed or denied, doesn't hold, he magically pulls a few chairs into the air and blocks off Marty's path to the barmaid, as well as Iamar's route to Marty

"Hold on Ma'am, we'll be surrendering in just a moment," He says to Iamar before turning his attention back to Marty. "Marty, as your friend, I recommend that you put down the weapon and surrender. Remnant probably has access to the best medical technology you could ask for and I'm sure they'll help you. That girl has nothing to do with your attack, let her be. Please."