Riddle

[Chuckers]

He had a white hat. In any case that he would have a red hat, one of the others would have been able to figure out their own hat color.

1w 2r 3r = one would know he has a white hat because he sees both red hats so he would have guessed correctly
1r 2w 3r = two would know he has a white hat because he sees both red hats so he would have guessed correctly
1w 2w 3r = 2 would know that he has a white hat because he knows that 1 didn't see two reds (or else 1 would know that his is white), and two sees that 3 does have a red hat, so he would know that he must have a white one.
Since neither 1 or 2 guessed correctly, they 3 knows that he must have a white hat.