The opposite of a blame culture is not a culture of refusing responsibility, but a system where you look for problems in the process when a fault makes it into the final product. It's always a mixture of specification, implementation, and QA that makes mistakes possible. Putting the blame on the engineer is not very helpful, it does little to prevent future problems. Trying to figure out how it was possible that an implementation bug made it through QA allows you to prevent similar mistakes in the future (at least if you're lucky).