Thanks. This 'under attack' and 'us vs them' really sucks. It would be unwise to form an opinion of the whole thing without actually reading all of the emails. Yes, there are ad-hominem attacks in the email you quoted, and even if ESR was right in everything, probably not the best way to express it.

Anyway, at least this outrage brought the issue into attention, now I'm super curious about this matter.

I'm reading his side first here: http://esr.ibiblio.org/?p=8609