It is likely Warner whould of played better than Matt but you can't say for sure.
He's had bad games before, and if he was woozy at all it could of been a nightmare of interceptions after a jarring hit or two.
So it worked out like it worked out and I would of liked Matt to move the ball better but if you asked me before the game if I'd take Warner not starting, a 4 point lead with about two minutes to go and them having the ball on their own 1 I'd of said Heck YA! and anyone with any sense would have.
He made several key plays, and played well enough to win the game, that's about all you could ask out of a guy who did not have first team reps on the road against a hot team.