How often do they get the answers wrong?

I was watching today, and they asked one contestant who the Greek god of love was, and he said "Eros", and the host was like, "NOPE. The answer was Cupid"

The contestant just kinda stared at the host for a minute, and then the host said something stupid about the staring, and the show continued.

I think after the show when he won, and they were all talking, it seemed like he brought it up though.