Are you sure he has no claws? I know when I first got my girl I didn't notice any nails/claws and it was only when she resisted climbing off my arm that I felt them and realized/experienced that chins have nails. Could it maybe be that you just haven't really noticed them yet? They could be short?
I'm no expert and I could be completely wrong, but that's just my personal experience. I hope it helps a little.
Maybe there just not that sharp, can u see little nails on his paws?
They also have an EXTRA sharp nail near their thumb area, i have scratches all over my arm.
But some have sharper nails than others, maybe he did his own manicure.