This is a common tactic when one of your accounts is frozen to ensure that you can't withdraw or use it as collateral in a loan. My guess, his account was frozen for suspicious activity or because of a request from some government agency.
The canonical example of why atomic database transactions are needed has always been transferring money from one account to another without creating a temporary imbalance.
Yet the actual real world financial industry has never solved the issue and doesn't care! It's just numbers...
"if you owe the bank $100,000, the bank owns you. But if you owe the bank $100 million, you own the bank."
Though I don't think it applies here ;)
const double ON_HOLD = -99999999699.99
A hold of ~100B and Chase’s reply that it is for different reasons. I’m sorry, what is a valid reason?