I believe the 'hockey stick graph' was looked at comprehensively by a US congressional committee who agreed that some of the statistical methodolgy was flawed but made so little difference that is was insignificant in the final analysis.
Anticipating this, the 'Exxon' led doubters set up through sceptic congressman Barton a parallel congressional comitteee, headed by a denier stool-pigeon ( Wegman?). Nobody of significance took any notice of their report apparently since the IPCC moved wholesale to the Hockey stick, slightly corrected and have developed it on further.
Nobody in the scientific community with any sense doubts it is the best collation & analysis of the last few hundred years (millenia actually) warming data even thought the uncertainties over proxy data are shared by everybody.
However, in the final analysis, it's a done deal and yet the denialists still think they will overturn the whole AGW concept by trying to reverse their previous routings - probability of that happening = the square root of sweet FA (polite version)
It's all in wiki btw
I didn't know until just now that Mcintyre & Mckittrick publish their first criticism in Energy & Environment