So based on those tweets, I suspect the following scenario is a possibility, or was perceived as a possibility by Amjad:
Radon interned at repl.it and asked a lot of questions. To be clear, asking a lot of questions is a good thing for career development in that it results in learning a ton, and typically something you definitely want your full-time employees to do, but not necessarily what you're expecting from an internship/temp worker arrangement.
Amjad apparently had some awareness of Radon being a particularly curious intern. Again, nothing wrong with that!
Radon then published an open-source hobby project which seemed to build on many of the teachings from repl.it. Based on what we can see of the discussion, it's likely that Radon wouldn't have had the exposure to the problem domain in order to build the solution he did, as fast as he did, had he not spent time at repl.it and asked a lot of questions.
Radon then showed this to Amjad, and as all of the above dawned on Amjad, he reacted incredibly poorly. The analogy he's using in his tweets ("someone goes into your house and steals from you, even if it's not material") suggests he's likening it to inviting a friend over to a dinner party at your mansion, having the guest ask a bunch of questions about the design, excuse themselves to use the restroom, and poke around in all the closets along the way. Next week they invite you over to the 1-bedroom flat that they regularly livestream from, and you see they've applied lessons they learned while asking questions and wandering around your place, to their interior design.
You don't feel robbed, but you may certainly feel a bit slighted. If you're a private person you might be a bit miffed about how your years of hard work has been distilled into something more spartan and put on display for others to copy.
Even if I think Amjad's response was quite over the top, I do think it's fair to be a bit surprised to learn that your guest spent a significant portion of their visit poking around in your closets instead of focusing on the dinner company. In the context of an internship, it comes across as mildly jarring to point out that you were actually just after interior design lessons rather than enjoying dinner for the sake of dinner.
I'm not proposing this is in reality close to what happened; Radon seems highly motivated and prolific, and was probably an amazing intern. I also don't think he did anything legally in the wrong, even if unconventional and potentially offensive.
Amjad's reaction was totally inappropriate, but based on his tweets there is at least some reason to the rhyme.