Explain to me the source code deal..
Would he not have had to make/have the source code to produce whatever product he gave him?
Of course, every coder relies on source code to produce a product. Correct, though completely irrelevant.
What would be his reasoning for not providing the source code?
Because JG didn't pay for the source code, simple. You get what you paid for, not what you
expect to get after paying for something. Basic laws of commerce I think.
Imagine you pay for a generic chocolate bar. Do you have rights to know the exact ingredients and method to produce it, because you are a customer? Should you expect a refund from your purchase of that chocolate bar because the creator/seller refuses to share with you the ingredients and production method? When you bought the chocolate bar, did it come with the rights to know of the ingredients and production method in order to replicate yourself? Do you deserve a refund on your purchase of the chocolate bar because the vendor refuses to provide you with exact ingredient measurements and production method? All of these answers should hopefully be self-explanatory for you, so I hope you see the point here.
Why someone wouldn't want to share their "secrets" is irrelevant to the conversation, unless you paid for this information, rather than the end result: the product.
He was hiring him to make a program, not buying an off the shelf program..
How do you know this? Why would it not have been an "off the shelf program" that had been modified for JG's benefit?
I can’t imagine apple or Microsoft hiring someone to create a program and not expecting to receiver the source code..
That's because a big corp wouldn't be dumb enough to purchase software without the source code, this has nothing to do with amateur deals.
The coder is under no obligation to share the source code unless it was clearly pointed out in the contract.
While I'm not fan of mindust, or mindrusting (no offence) - then this is the point here.