OK something I've never understood in this case
If, and it's a big "if", he really did invent Bitcoin (original BTC), then he can prove that by a) telling people he's going to move a bit from that 4.5bn he claims to own; b) transferring a minor wedge into another wallet that he owns and to which other people can see, and c) transfer it back if he wants. Do that, on video if you must, and boom everyone will believe him. The fact that he hasnt done something that simple, says he's a liar.
So ok Hackers stole his "keys" to this forked Bitcoin, which I assume was forked 1:1, so he's claiming the same ownership as in original Bitcoin. Is he also claiming that Hackers stole his keys to the original Bitcoin wallet too?
If so, well frankly then he's an idiot for not having everything offline and backed up. If Hackers had really stolen the keys to his bitcoin, those bitcoins would be making their way through tumblers, etc. and into bank accounts somewhere else. That they havent moved at all, says to me he's talking bollocks. More likely (again making the rather reaching assumption that he really does own them), he's simply forgotten the passwords, or lost the keys on an old harddrive that went to the tip. No back-ups and bye bye.
But then again, I'm willing to bet he's talking out his arse... But as always, let see what the courts decide...
Biting the hand that feeds IT
