The point being made is how bugs invoke an automatic admission of guilt in developers, and absence of which shouldn't be seen as not taking responsibility, especially when tranches and layers in the system (built over the years, say) could have made the entire debugging and development process cumbersome, uneasy, unconventional, unyielding, dense, exhausting, and frustrating.

Taking responsibility might involve any among:

- documenting the behaviour for future maintainers.

- writing tests.

- identifying and pushing the management to fix technical debts.

- digging up the root-cause to fix deeper flaws, if any.

- advocating for saner development and deployment practices.

- ...