Earlier quoted context omitted.
Or they lost the key to the wallet before the tokens were worth cashing out.
this is evidence that he wasn't in it for the money. If you came up with an elaborate scam with intentions of hustling people - how likely are you to be wildly successful, but accidentally lose access to the funds you worked so hard for?
I could just as easily come up with a post hoc story that says that the reason that he has never come forward to claim credit is out of extreme embarrassment about the size of the fortune he lost, and that this is evidence that he does care about the money.