[djur]

A lot of other people have flagged the remarks about "yelling in chat" and the like, and those are certainly red flags, but I think what you're pointing out here is the biggest problem. "Write code on paper" and "write code unattended" are not the two only available options. Worse, from the description of it as "a very simple change", it kind of sounds like he was giving them the same type of problem to solve in both cases.