I am very saddened. (Okay, that's a lie: I'm boiling with anger and I want to publicly beat you both up, evict you from the tribe and rule as alpha.) I expected much more civility from you both.

AFAICT the reason it started escalating is that neither of you made an effort to smooth over small status aggressions. ("Citations are otiose.") That probably comes from hacker culture that prides itself of being concise and to the point with little regard for social implications, until someone gets told to choke on a bucket of cocks.

He got very angry and very rude over small aggressions, though, and his personal stress is not an excuse. But you were in the wrong as well to keep talking when he told you to shut up, that was provocation.