I'm going to kill management.
After a serious migration fiasco at one of our biggest costumers the platform was finally usable again (after two days instead of 10 hours) and, of course, users started to report bugs. So good old po came in ranting that we as qa did a horrible job and basically tried to fault us for a fucked up update (because we produced user pain, which of course not being able to log in didn't do). Among the issues: If the user has more than a hundred web pages the menu starts looking ugly, the translation to dutch in one string on the third submenu of a widget doesn't work and a certain functionality isn't available even if it's activated.
Short, they were either not a use case or very much minor except for that missing function. So today we've looked through the entire test code, testing lists, change logs and so on only to discover that the function was removed actively during the last major update one and a half years ago.

Now it's just waiting for the review meeting with the wonderful talking point "How could effective QA prevent something like this in the future" and throwing that shit into his face.

I mean seriously, if you fuck shit up stand by it. We all make mistakes but trying to pin it on other people is just really, really low.