I try to be responsible for my department. If something goes significantly wrong I don’t look for excuses, I wear it (of course, if something goes significantly well I make a note of it and bring it up at the next performance review).
Admitting to an epic screw up makes me feel like I have failed. But I find that failure is like a wound, it heals, and can be superseded by the next epic achievement, and rather than being the road block, becomes another stepping stone – left behind, but helping you on your way.
Excuses and blame make me feel guilty. Guilt is more like a virus. No real cure, apart from admitting to failing.