Simple greed. AS you pointed out, it makes no sense, which gives him the perfect cover. He can empty the coffers and claim it was a hack because of a technical

Simple greed. AS you pointed out, it makes no sense, which gives him the perfect cover. He can empty the coffers and claim it was a hack because of a technical glitch. He takes it all, declares bankruptcy and he's gone with the wind. Now, with a hefty stash, he can start another BTC exchange, and then rinse and repeat as necessary. It's about as close to a perfect crime as you can get.