“Real circumstances” in the “real world” have a way of correcting false views of prophecy. That’s generally true, unless someone is so far out — and “off” — that they cannot even connect with reality, and in that case they make up some very elaborate “cover story” to explain it away.
I think Camping probably believed what he was saying - however - he was simply wrong, and he recognized that he was wrong. At least he did realize that he made a mistake (in his understanding).
He recognized he was wrong? Sure, he did. I remember how he “corrected” his prediction to take place a few weeks or months later.