I take a similar approach to Mprep, in that if the majority of the post is on topic, then I'll likely leave it. After all, I think we all stray somewhat off topic, but as long as we keep the main point on topic, and the majority of the post on topic I don't think it's that big of a problem.
Another option might be that it is not acceptable to repost a post that was previously deleted by the moderators, without permission from a moderator, or that you cannot take action to reverse what a moderator did, unless you are complaining in meta, or have received permission to do so.
As far as I know, this will likely lead to harsher actions being taken if this continues. Likely starting at personal messages warning of the fact, then leading onto a temporary ban. Though, I've yet to be in this position, most people aren't that persistent, and just accept it or complain in Meta which is fine.
My biggest concern is that someone who is complaining should know where to complain about the moderation. Almost all the time, if a post is moderated, the moderation follows forum policy. However there is always the risk a mod goes rogue, or a mod account gets hacked. If this happens and people complain in the wrong section, the administration will have difficulty detecting the moderator doing something he shouldn’t be.
Yeah, in a perfect world that's what would happen. Though, I'd like to think that if someone was being punished unfairly or at least suspecting that a moderator has gone rogue as you put it, contact an admin to get it sorted or at least look up where to post complaints.
I'm not sure how much this has happened in Bitcointalk's history though, I don't think I recall many instances, maybe once? So, either the admins do a good job of getting on it right away or it just doesn't happen very often.