Many years ago, I found a piece of corporate code that stopped working when a specific person ID was not marked active in the Users table in a DB for a specific

Many years ago, I found a piece of corporate code that stopped working when a specific person ID was not marked active in the Users table in a DB for a specific application. That person was the long-time developer responsible for supporting that application, who finally happily retired. This took a while to happen, since that DB was not kept updated very well, it was easy to find, and nothing malicious happened. Just some bad debug code that made it into prod.