My dad was an accountant. He had one business client who, it turned out, had an employee at one of their sites (blood collection from individuals with rare types, for processing into medicines. Mostly paid in cash) stealing from them for years. When they finally decided to do an audit the employee called my dad and said her records had been accidentally destroyed by a flood and begged him to help cover up their loss by faking them. Needless to say he declined and the audit uncovered her crime. They didn't prosecute her, they just fired her.

Another time a friend had a neighbor who ran a lucrative business that did plan checking for city permits. Their office manager had been stealing from them for years also, enabled by their antiquated paperwork-based accounting system. Every time the owners suggested upgrading to something computer-based or having outside accountants come in, she'd thrown a fit and they backed off because she'd been with them from the beginning. Then, finally, they went to sell the business and the prospective buyers insisted on due diligence and the jig was up. She'd taken them for hundreds of thousands over the years. They didn't prosecute her either.