Nice catch mate, was this done manually or automatically through a bot?
It wasn't me who reported him, probably suchmoon. All I did is check a few posts made in June and July (manually), this one stood out and I got a match.
That's a good practice (

) to check for outstanding posts.
I usually start from the really first post of the member and you can find really strange things from the time when the member was a newbie, usually there are posts with different language, before it changes to english speaking one-liners...
And if you find some longer posts between those one-liners, now those worth a check. So basically you don't need to read thru all the posts of a member, just check those that are different. You'll see that those posts are usually a catch, so you can be more effective.
But everyone has his/her own know-how for this job I guess

Searching for plagiarism in user's post history unfortunately is often tedious and time-consuming. Sometimes even Google doesn't get a correct match, sometimes there is word-spinning involved, etc. That's why I'm usually meriting those examples posted in appeals threads - I know it takes a lot of work and/or luck. That's why the "I only did it once" excuse is nearly impossible to prove and may take a lot of effort to disprove unless the perp is a total shitposter.