I guess you are assuming that they did not employ an accounting firm or accountants to assist with the design of their system?

If that is the case (non-accountants attempting accounting, or not bothering, perhaps) then you have a point… but I doubt that is what happened.

It would be grossly negligent crossing into malfeasance, and probably criminally illegal to operate a money business without proper accounting supervision (and accounting is a regulated, qualified profession similar to law)

But, if that is indeed what happened, I look forward to seeing the founders in federal prison. I just kinda doubt they ran a banking startup without ever consulting a lawyer or an accountant.

...Because there are no shady accountants or lawyers more motivated by a quick buck to be made, with the wherewithal to stay reasonably distant from anything blatantly capable of blowing back on them. Surely.