Sounds like a scam written all over it. I only ship until AFTER all and any funds have cleared. I bet his "partner's" check would have bounced to the moon. I would have politely told him that I could and would only ship until after the check had been cashed and cleared and that this could take a couple of weeks. If he insisted on shipping, I would have just told him he's going to have to wait until the check clears; no ifs ands or buts.

But in the end, they're your snakes and you produced them and shouldn't sell them to someone you don't feel comfortable with. I've turned away potential buyers just because it seemed to me I'd be sending my animals to a negligent home or something. In the end, I think you were right in not selling to him.