I am not sure moderator has a same power, lock a thread and the author can not unlock it like global moderators and admins.
This is also available to regular moderators. Once a regular moderator blocks a user's topic, the user will not be able to unblock it himself.
About the post you showed as an example only Xal0lex, who made the edit, can answer though. I don't know what changes he made in the post.
In this particular case, I reduced the picture in the quote to make the post more readable. Quoting large pictures is not a rule violation, rather it is a matter of aesthetics, as the post looks bulky. I very rarely resort to editing posts, it's mostly about merging consecutive posts from the same user, overquoting, etc. In this case, the semantic content of the post itself is not affected.