So he deposited 200 BTC according to his wallet transactions today and withdrew 100 BTC and is still missing 100 BTC?
It doesn't make any sense as to why he would deposit 100 then withdraw 100 10 minutes later then again send 100 and now claim a scam.
He already explained this:
(I always make it a habit to put my coins back into my wallet after playing on any site.)
It's not uncommon for people to withdraw at the end of each session so they know their coins are safe in case "something happens" while they're offline.
I don't know how his 10 minute session went. Maybe he lost his first bet, struggled for 10 minutes to get back to breakeven, managed it, then withdrew.
It certainly doesn't look suspicious to me.