The scope of work failing to cover the necessary work discovered by billions of dollars is still pretty fucking serious no matter how you do the accounting.

No, it’s not.

If I pay you to redo my floors, and while you’re doing it you discover that a pipe beneath them is leaking and needs to be fixed, that’s not an accounting issue, that’s not a problem with the contract to redo the floors, that’s just an unexpected issue that was only discovered when you did the previous work.

That happens literally all the time across all types of projects.