The Blame Game

I am a man of many faults (not of constant sorrow) but I always take the blame for my mistakes. I hate finger pointing, especially when it is to divert blame. I work in a field where putting on a newscast is really a team project. And if one member doesn't do their job, the entire show could be in danger of blowing up. Now when I make a mistake, I own up to it and try to learn from it. Others it seems think they and their department can do no wrong and since I am at the end of the line before it hits air, I should be responsible for fixing their mistakes. Unfortunately for them it doesn't work that way. We had a problem the other day where A+B+C=D, now I am 'C" and "B" didn't do her job so "D" got messed up. "B"s boss tries to pin it on my and I respond that if "B" did this then it wouldn't have happened. Bossman says no I am to blame and I state again if "B" had done their job all would have been right with the show. Then Bossman says, "All this other bullsh*t aside, you pressed the wrong button". And I say "No, "B" didn't advance the stories to clear the machines, I pressed the RIGHT button but because the machines weren't cleared by "B" the wrong thing was on the air."
Bossman says "Oh, thank you for your time."
Fifteen minutes of my life gone because people don't like shit in their own backyard.