I'd be more than surprised - I'd be completely and totally shocked ( ) as the rules are quite clear on this and I doubt very much if a winning or losing pitcher has ever been "changed" after the fact - it's not a judgement call for the official scorer.

There are certainly cases when the way a winning or losing pitcher is determined may seem unfair (altho I don't necessarily think that this is one of them), but they're not gonna change the way they do it to accomodate this one game, or make an exception for it.