Yes, but what I mean is - if they were not created immortal (I agree), they presumably expected to die at some point. Well, 930 years is pretty much the best innings any human has ever had! Perhaps slightly exceeded by others in the OT, I can't remember. But if someone told me "you'll die today" and I lived to 930 years, I'd feel pretty pleased with myself, and I certainly wouldn't expect that person to be there at my death bed saying "ha ha, I told you you'd die "today"! Neither would be thinking "darn, if only I hadn't eaten that fruit..." - I mean, 930 years of carnal life is actually too much! I think I would probably have preferred to die on that day (or some time in the near future) than live for nearly a thousand years of toil. If God had said, "on that day, you shall be given a thousand years of hard labour", it would make more sense!
Essentially I think it sounds like a bit of a "get-out", a way to make sense of something we don't really understand... I mean, when theoretically would Adam have died, had he not eaten the fruit? He's not immortal.
Something that just occurred to me is this: imagine you give a child a lightweight, toy bike. It's nice, it works, but it's not very robust. Still, it's a gift, and it pleases them. You say to them, "don't go over the rough ground on your bike, because it will break, and I'm not buying you another!". Of course, you know the child will, out of natural curiosity and rebelliousness, go over the rough ground. But what they don't know is that, before they've even broken the bike (inevitably), you have bought them a bigger, stronger bike that will last and is perfectly capable of going over rough ground.
Their bike breaks, they cry, they scuff their knee. They suffer both physical pain and the loss of their original gift. But when the time is right, you show them the better bike you had for them all along. Their experience on the little bike means that they truly value the strong bike. Despite the fact they think they were rebelling against you in going on the rough ground, they were perfectly fulfilling your plan which, in love, was for them to have and to appreciate the sturdy bike.
Perhaps Adam's death is the breaking of that toy bike? Was he already defiant, or carnal? Yes. Was that inevitably going to lead to "death"? Yes.
Ray's reply is profound. Adam's "death" codified the consequence of his carnality, in the same way that the Israelites could steal before they received the law forbidding theft. They were being carnal alright, but they weren't breaking a law because it hadn't been given to them. Afterwards if they steal, they invite punishment and consequence upon themselves, and it is given to them for them to understand this causal link between sin and death. Is any worse harm caused in the physical realm by murder before or after the law? Of course not - it's traumatic and saddening in both cases. But after the law, the murderer understands his actions lead to death, and that his carnality is responsible for his downfall.
Quite what Adam understood at the time - if you believe in a literal Adam, Eve and talking serpent - I don't know, but the record is kept for US to understand.