The one we get to hear about.
Probably because he was greedy and pushed his luck.
Years ago I heard from a mate in the payables unit of a large U.K. company that, routinely, bills below a certain threshold would just be paid blindly because the resources required to check, cross-check etc. outweighed the (relatively) minimal cost, especially if it meant verifying with other departments.
Coupled with the fact that - came across this more than once with other guys I knew - many large companies particularly those with payments crossing borders** would have VERY shonky invoicing systems in place “somewhere” which meant management were very nervous about a lowly payables clerk - or anybody - asking too many questions..
**Pssst .... petroleum-related.