How can this be provably fair play? They don't give an irreplaceable Server Seed Hash like on Stake.com or any other casino
What do you mean? They give you SERVER SEED HASH before each roll, and SERVER SEED after each roll.
You can verify that the number you rolled was indeed provably fair here:
https://s3.amazonaws.com/roll-verifier/verify.htmlThe guy probably doesn't know where to find the server seed hash on the site. Freebitco.in was the first ever dice site I encountered and they are the provably fair site I played too. I wonder what confuses him if the hashes can be found after every roll, unless the guy has some hidden agendas, it's fishy.
You can easily find sample scripts from internet to verify each open number automatically.