This is some kind of a follow up of this same old issue where the problem was, that a malicious troll managed to split the moderator/administrator team of our small community.
The situation has now clearly boiled down to the fact that two "good" administrators want the site to be high-level and professional, whereas the third "bad" administrator does not recognize any rules, responsibility, despises any form of authority and wants to turn the site into an anarchistic crackpot forum. The third administrator joined the site and the team later, and he never accepted what the previously existing community has decided that the site should be. Yes, we should never have made him an administrator ...
Luckily, the "bad administrator" has been busy with real-world issues during the past few months, such that our site could thrive and continue to attract the right kind of professional audience. But after his favorite crackpot (The one he always wants to protect by all means) has been warned for off-topic commenting in accordance with the site rules, the bad administrator became very upset.
In private email discussions he insulted all other members of the moderation/administration team. On the meta part of our site, he and about three of his friends (including the crackpot he protects) try hard to get the long standing, agreed upon rules changed, by misrepresenting what they mean and how they are applied. He dishonestly misrepresents and distorts what other people have said and done, and he even copies parts of the private email discussion into the meta part of the site to pursue his campaign of turning the site into a crackpot forum and making everybody who opposes this look bad.
The problem is that at present, nobody apart from the trolling administrator, his friends, the crackpot, and the rest of the team are active on meta. So it is actually the people who always wanted the site to be high-level and professional that are looking bad and are seemingly in the minority, even though the silent majority on the main page would tend to support the original goals of the site.
So how can we save the community and prevent it from falling into the hands of the trolling administrator and his friends, without alienating or frightening the nice people who are active only on the main page and don't even notice the ongoing meta fights?
What I already did is to start writing to high-rep, community trusted and appreciated users, in private, if they could have a look at the issue and help.
Kicking out the trolling administrator which would, as he never accepted the goals of the site, be some kind of the right thing is dangerous. The trolling administrator can contribute good content if he wants too, and is therefore popular.
Calling in the owner of the site, who wants it to be high-level too, also bears the potential danger of deadly disrupting and frightening the community.
Giving in and handing the site over to the trolling administrator and his friends is no course of action we want to follow.