Tyler Cowen offering a reason why the CRU hacked emails should raise our confidence in AGW...

That's not what he is saying. His argument is not that the hacked emails actually should raise our confidence in AGW. His argument is that there is a possible scenario under which this should happen, and the probability that this scenario is true is not infinitesimal. The alternative possibility - that the scientists really are smearing the opposition with no good reason - is far more likely, and thus the net effect on our posteriors is to reduce them - or at least keep them the same if you agree with Robin Hanson.

Here's (part of) what Tyler actually said:

Another response, not entirely out of the ballpark, is: 2. "These people behaved dishonorably. They must have thought this issue was really important, worth risking their scientific reputations for. I will revise upward my estimate of the seriousness of the problem."

I am not saying that #2 is correct, I am only saying that #2 deserves more than p = 0. Yet I have not seen anyone raise the possibility of #2.