You are the management. It's always your fault. If you didn't actually write the bug. You could have trained the person who wrote the bug. You could have reviewed her code. You could have not let them check it in. You could have not let them work on the feature. You could have not hired them.

You could have fired them.

All this helps you do in a twisted way is figure out who you should fire. Chances are people will leave long before that.

Even though I'm not the boss of my team. Our policy is that it's always my fault. I find it liberating. Gives me an opportunity to learn from all our mistakes. And there is no finger pointing. Unless its at the management. As its always the managements fault.