No payouts for double-spenders and cheaters!
You have no proof that he cheated. You have no proof that his intent was to double spend.
Prove that he actually had an intent to double spend, because looking at it from my view (and probably most people's), he wanted to make multiple bets, and you didn't accept multiple bets in one transaction, so he decided to make 10 transactions. The fee he paid is decent and could expect to be in the next few blocks.
He chained every bet. That means, that if one is double spent, all the ones after are also double spent. This gives less control, making him unable to only double spend losing ones (assuming that was his intention)