At this point he could not see my screen (he was standing directly in
front of me), but offered me a simple bet – He said if I sent him the
picture of the girl he could find out her name.
Reminds me of:
Sky Masterson: One of these days in your travels, a guy is going to show you a
brand-new deck of cards on which the seal is not yet broken. Then this guy
is going to offer to bet you that he can make the jack of spades jump out of
this brand-new deck of cards and squirt cider in your ear. But, son, do not
accept this bet, because as sure as you stand there, you're going to wind
up with an ear full of cider.
> Simplest explanation: Someone saw you and told him.
Of course one of the first things I did was ask another friend who I thought met her. But no, ultimately the answer did come from the internet, not from anyone I knew.
Simplest explanation: He knew before he made the bet.