Comment by tavavex

Yeah, I don't mean to justify the actions of the interviewer, they were likely in the wrong here. It's just that, to someone in my position, it seems almost funny to be willing to throw the entire interview over something like that. It's them who gets to decide your fate.

Also, we can't know what exactly was said, so maybe miscommunication could be partly to blame. Like, "Are you sure I can use any language? (Are you really so gracious as to give me this option?)" vs. "Are you sure I can use any language? (Can I use something you definitely don't know?)"