[ He could switch their positions so Emet is the one holding the knife. But it won't change anything, he could still drive it into his own throat. It's just a dream. So even if Emet was killed in it, it wouldn't be an issue. It would be nothing.

But he can't be rational about this. There's an outright sob escaping from him when Emet places his palm over his eyes and nose but he knows what he's aiming for and he decides to just give it to him, activating his ability to travel through time - bringing them both back to the platforms from earlier, before he was even paralyzed ]