I haven't had time to read John Mashey's report, but from what I can gather about today's excitements over the GMU investigation of Edward Wegman, there are two possibilities in play:
- Wegman et al are guilty of plagiarism; short-centred principal components analysis is biased and can produce hockey sticks from red noise
- Wegman et al are not guilty of plagiarism; short-centred principal components analysis is biased and can produce hockey sticks from red noise.
Is this right? Nobody is suggesting that the principal findings of the Wegman report - on the incorrect centring used by Mann - are incorrect, are they? They were, after all confirmed by the NAS panel and apparently also by David Hand during the Oxburgh panel's (brief) deliberations.
So I guess we are looking at quite an interesting investigation about how the norms of academic citation apply in expert reports (no doubt Donna LaF will be checking the IPCC reports over very thoroughly in coming days), but not much else.