I'm glad it wasn't anything worse and I hope he didn't get away with too much money. I'm thinking at that time of the morning, you probably didn't have a lot left.

It is more likely the loss of the purse and any sundries that hurt.
That was something I was also doing this time. When I saw a bike coming towards me, or noticed one coming up behind, I'd swing my arm in so that my purse wasn't grabable. And another reason why I never carry more cash than I needed that night.
But these things can happen anywhere. My friend was in Brazil, in a crowd of people, in broad daylight. She had her camera on her wrist and someone grabbed it. She said she didn't fight it at all, her concern was getting her wrist out of the strap before she got hurt.