It will only look like it kills you in advance when the death is "unavoidable" i.e. you would have died regardless. If you do a run with vpatch and die, then play it back with non-vpatch, it'll look as if you died the frame before. If you do a run without vpatch and die "the frame before", if you play it back with vpatch it'll look normal. It's the same thing.
This isn't an issue that actually affects the game, it's an issue that affects the player's perception.