It isn't pig-ignorance to ask a pig-ignorance question at all, it just makes it a lot easier for an Interviewee to appear even more coherent than they might otherwise be?
It's dragging on and Interviewers are running out of questions to ask; and there's a kzillion hundreds of nondescripts around waiting to be asked more of the same questions.
Don't read more into it than there really is - which is nothing.