Nope, not failing to understand, not by a mile. Simply trying to look at it from different angles as a neutral third party to this situation, seeing if I can make sense of it. Clearly, there has been some miscommunication somewhere between customer & vendor, and I hope a mutually agreeable outcome can be reached. EBay and what happens on EBay are not unknown to me, and usually it works out for the customer IME.
What I don't know, for example, is if he told you he is a trucker (earlier than the post in this thread, when you contacted prior to purchase), but those guys are on the road for days at a time. So that 5 business days, I am assuming, is to allow for those times when the purchase is final, and he is not able to ship right away due to not being at the item's location. Just guessing.