That user violated several
forum rules:
-snip-
27. Using automatic translation tools to post translated content on local boards is not allowed.
33. Posting plagiarized content is not allowed.[e]
33 [e]. This includes copying part or all of the posts or threads of other users and copying content from external sources (eg other websites) and forwarding it as your own.
The rule is clear enough.
And IMO that's enough for the mod to ban that guy.
Most frequently, in most forums, mods will give forum members many warnings before handing out bans, especially permanent bans unless they are doing something especially damaging or egregious (such as spreading malware, or unfortunately seems to be a problem here, plagiarism).
You can send him a PM if you have concerns about him using automatic translations with a source that it is against the rules, and if you continue seeing him do this, you can complain about him.
Neither of the cited posts are plagiarism, at least not the portions of which he is talking about those books because he is at least making an attempt to cite the author as the source. If there is another writing not by the author that makes similar comments, it would be plagiarism.
It is possible he took his 10 day ban as a warning to put more effort into his posts.