A manager would certainly argue the other way around: The person who created the bug costs the company a lot of money. Fixing that single line was just necessary because someone didn't do his work in the first place. So fixing that line is something you should do off-the-clock.
This is just one of the reasons why I appreciate it when managers have at least some coding experience.
To that manager: that bug wasn’t the creation of a single developer. It went through code review. It had unit tests. A QA verified its initial implementation and a Product Owner signed off on the feature as done.
If it wasn’t caught before prod, it’s either such an edge case as to be almost impossible to catch OR (more likely) it’s representative of a systemic failure within the organisation.
This is just one of the reasons why I appreciate it when managers have at least some coding experience.