Pikachu vs Snivy was bad. I get that Zekrom nerfed Pikachu, but still, the decision to even have that be a thing was really, really dumb.
Ash vs Cameron was something else in the worst way possible. These two battles make it really hard to defend BW, even though I actually liked it for the most part.
Ash vs Hau wasn't great, but at least just save the dumb owl napping for the end so it looks like a double KO, but he wakes up before the ref's call. Also, maybe don't trust an untrustworthy pokemon to come through for you next time, Ash.
No, I wouldn't overturn the result. Calling a sleeping pokemon KO'd was a decision done by one dumb Kanto ref in the middle of a series that was more "anything goes" than any other in the show's lifetime, and was a decision that was literally never referenced again because there hasn't been a sleep = KO call since. The only thing Hau got robbed of was the opportunity to get curbstomped by ya boy Guzma.