Simon, editing the content of somebody else's post is somewhere between wrong and illegal.
You can always delete the post entirely, or ban the user, but do not edit the content. I live in a former dictatorship country, and I mean it when I say it was wrong what you just did. The fact that is technically possible to edit, doesn't mean you should do that. I did forum moderation for many years, and seen a lot of crap, from spam to personal insults.
Anyway, editing is both wrong and time consuming, it is like you would lie about what somebody else said. Just delete the entire post and move on. Nobody will give you back that time spent editing.
I tend to agree. Moderators editing comments, no matter how small, changes the forum into an editorial, and the authorship of a comment can never be truly trusted. I've seen forums devolve into censorious echo chambers and moderators editing comments was a key part of that (comments could easily be edited with no "
edited by:" notes attached to posts)
Sure you can argue it's not the same extent, but it doesn't negate my first statement. It's just a bridge you can't uncross.
Any open forum has to deal with spamming, low quality or trolling posts. I've always thought a better option was either the ability to hide posts, or in the worst case every thread has a parallel "naughty bin" thread where bad faith or trolling posts could be placed unedited.
Sure, it also has the ability to be misused or applied with bias, but it isn't censorship or editorialising if you can choose to read the original unedited posts, no matter how garbage they might be.