Isn't this statement contradicting itself?
The word "misconduct" implies bad intent. This was a moderator getting tricked.
Since Ratimov was turning his old topics into garbage on purpose
He wants to delete his posts, but he can't delete the topics, so he's editing them to be "blank". This is common and allowed.
then he moved his trash in the Russian local board
This is a rule violation, but it's fairly minor. A veteran forum member isn't typically going to be banned without warning for moving their topics incorrectly. (These topics were blanked and then deleted over the course of ~3 days before the issue was noticed. It wasn't part of an ongoing pattern AFAICT.) If he continues to move topics incorrectly, this would warrant a temporary ban.
I would argue that even self-mod threads that Ratimov cleaned out should be restored and locked, if that's not done already.
It's allowed for topic-starters to delete all replies to their self-mod topics. Restoring the posts would only be considered in special cases such as if their account had been hacked.
Also, if a topic has no more replies, moderators will typically delete the topic on request, since then there isn't the issue of deleting other people's replies.