In my opinion this is a massive over reaction to a decent performance capped with a good goal.
He did well in a difficult game for him. But nothing special, certainly nothing I saw warrants you thinking he's been the dogs bollox for months :S Henderson too, deserves credit for being in an unfamiliar position and working hard, but certainly didn't play that well in my opinion.
Have to disagree with that (as you suspect).
Carroll has been under enormous pressure, particularly of late, and especially after the Newcastle game. Perhaps you view his performance as "average", but you have to admit it's a significant step up from what we usually see from him. And he managed to score a crucial goal. He also spent a large percentage of the game defending - that's going to hurt his prospects of scoring goals.
Henderson too did more than you suggest - he provided one or two really good balls in, and went past his man more than once. That's a really good effort for someone playing hopelessly out of position.
For once both these players didn't look entirely out of place wearing red - and that to me means they had really good games. Perhaps it was a flash in the pan, perhaps it was signs of finding their feet. Your mileage may vary.