Has someone who’s interviewed candidates that do this, I like to think it’s fairly obvious when the candidate doesn’t actually know what they’re talking about.

I've seen this and it is always super-obvious when they are reading instead of having a conversation. I wish candidates would just stop: some of them we might have otherwise have hired, but instead it becomes a waste of time for us and them.

They do do that. If it was merely for translation it would be okay, but usually it doesn't stop there.