Massaging data does not negate the claim. Your claim is "AGW isn't happening". This isn't supported by "CRU massaged data". Massaging data doesn't prove or disprove a thing. It simply proves that data trends were smoothed.
Scientist: It is 80 degrees outside. It should only be 79. The Earth is warming.
Normal Guy: Wow, that's bad.
Whistleblower: Scientist changed his data so that it showed 80 degrees.
Normal Guy: Scientist, what temperature was it really?
Scientist: . . .
Whistleblower: We don't know what the temperature really was because Scientist won't release and/or destroyed the raw data.
Normal Guy: Scientist, is this true? Please show me the raw data.
Scientist. I don't have to. The Earth is warming.
What is the logical conclusion for Normal Guy?
1) The world must be warming anyway. The lying, scheming, data-hiding scientist surely must have a good reason for lying, scheming, and hiding data.
or
2) If the world was really warming as Scientist says, he would have no reason to lie, scheme, or hide data. Therefore his entire asertion that the world is warming must be false, or at the very least, unsupported by any evidence.
I think the conclusion is fairly obvious.