Even pre llm, there was a clear indicator of someone who was skilled at coding versus someone who was not. The big thing that differentiated people was curiosity. When someone is curious, they would go look stuff up, experiment, figure out how to build things by failing over and over again, and eventually they would figure it out, but consequently, they have learned quite a lot more along the way.
And then there were people that were just following instructions, who in interviews though that them following instructions was virtue worthy.
Nowdays, this is even easier to tell who is who, because LLMs essentially shortcut that curiosity for you. You don't have to dig through the internet and play around with sandbox code, you can just ask an LLM and it will give you answers.
This is why I specifically said if you are hesitant of starting with LLMs, you should learn how to learn first, which usually starts with learning how to ask questions.
In my opinion, it is extremely important for the interviewer to realise that they are in a dominant position. Here, I can tell you what I think about how you judged me. If I was an interviewee, I may not be in a position to lose the job just because I told you that you are being rude.