TLDR: I don't like this game.

Kind of scammy if you ask me. Intended to have more than 2 participants trying to match each other, you are almost guaranteed to never pay in this game so the expected return for players is negative.

You need a contingency for really high-ballers. Node has no 1BTC liquidity or you have an emergency sock-puppet to out-bid the high-baller. After all, you introduced no check on timestamps, so you could always fit in an event after high-baller and before timeout. And so could they ... ten minutes later and nobody would have proof of anything.