This looks like some sort of money sink he's ashamed to admit having. Might be gambling, might be porn. Whatever it is, it's not something he'll garner any compassion for.
As per his cold emails and interview patter, it is my opinion that he will have considered defence and mitigations arguments to present in the interview.
Many people don't understand how serious gambling addictions is. It destroys families. I can be as bad as any drug related addiction if not worse.
Though that was just one guess. There are many money sinks. Porn, gacha games and so on.
He withdrew $1,000 from the ATM from his home back in Asia. Was duly given the cash. He noticed though, that looking at online banking, his balance hadn't changed. Odd, but maybe it was a vagary of international transactions (and again, 20+ years ago).
Nope. So he took out another $1,000. And another. Every time, got the money, no transaction posted.
Not just one ATM, any.
Over the course of 2 years when it all came out, he had gotten $2M+ from this.
Know how he got caught? He took some of that money gambling. And sat at a table all night, constantly replenishing his stash. That tipped off the casino that something was odd, because they had loaded the ATM with $250K, which usually lasted ~48h, but he emptied out in a few. "Didn't we fill this this afternoon?".
Once they got the financial institutions it was also fairly quickly revealed.
And in court, the local banks admitted that there had been nothing flagged in their system, and presumably it would have kept working until (at least) his card expired.
There you have a literal money printing machine, and "No, let's see what I can win gambling". I suppose here's other factors like "Maybe it's easier to launder a big winning" but nonetheless, it actually appeared more that he was just addicted to gambling.
Presumably he expected the jig to go up eventually and be asked to return the money; if his gambling was successful he could've returned the money and avoid any trouble, essentially having made his winnings on credit.