A bar can prove that fairly easily. Show expenses, show receipts. Show auditors that the place is packed every weekend.
This isn’t about honest businesspeople having to meet some impossible burden of proof. This is about selling 10 million worth of product and not bothering to figure out where the money came from.
The author is showing expenses and receipts of purchases. They are extremely clear and in some cases easier to track to owners than dollar bills. A bar selling alcohol for dollar bills would have a far thinner paper trail than what this author is providing.
