By my reading of that thread, he was not leaning on his own authority but on that of an academic consensus. James Miller replied by claiming to distrust academia in general on the matter, and mentioned relevant incentives that might push them towards an incorrect conclusion. Gleb replied that "peer review is peer review". Up to that point, everyone was being reasonable.
Then VoiceOfRa jumped in, was very rude and seemed to thoroughly misunderstand what was going on. See this comment where he says:
For example, you've claimed several times that people should believe you because you are an academic historian.
But both of those links lead to comments by Gleb which link to sources!
this comment: (By Gleb)
http://lesswrong.com/r/discussion/lw/mzw/link_a_rational_response_to_the_paris_attacks_and/cwzh
includes the line:
Do you consider my credibility as an academic historian to be evidence?
Before seeing that comment I was confused as to whether Ra was talking about words (that Gleb said) to the effect of that or literally those words; now I see it was those words exactly.
this thread also brings to light something interesting:
http://lesswrong.com/r/discussion/lw/mzw/link_a_rational_response_to_the_paris_attacks_and/cx6p
...Gleb: I c
Richard Kennaway has posted about an edit war on the wiki. Richard, thank you.
Unfortunately, I've only used the wiki a little, and don't have a feeling for why the edit history for an article is inaccessible. Is the wiki broken or has someone found a way to hack it? Let it be known that hacking the wiki is something I'll ban for.
VoiceofRa, I'd like to know why you deleted Gleb's article. Presumably you have some reason for why you think it was unsatisfactory.
I'm also notifying tech in the hope of finding out what happened to the edit history.