Then he remembers that he spent some time the night before sitting on a roof with his mate. His mate says, "Sure, you had your wallet with you."
So he hurries to the place and there's the wallet- lying on the roof- untouched.
Only thing is he knows it had £100 in it when he lost it and now it has £150.
I got this story from the young man himself. He didn't volunteer it. It just happened I was around yesterday when he was panicking- and today I asked him how things had turned out.