I worked in a pharmacy with an older woman that did that. She was "officially retired" but she still worked one shift a week. She would take a $50 or $20, depending on what she had in the drawer, then she would eat something she was allergic which caused her to shit her pants so she would have to leave without counting down her drawer.

We would get saddled with the count down and the over/short form because her drawer was off by more than $5. So it made all the supervisors look bad because our names were on her drawer every week. We all knew she was doing it but we had zero proof and my boss was too much of a softie to let her go for the shitpants thing.

I moved on to better pastures after 5 years of dealing with that particular brand of hell, but I did hear she finally got caught a couple of years ago. She admitted to regularly stealing money and she was fired but they never pressed charges. Unfortunately the company's refusal to press charges against theft and assault of employees is a whole different issue.