Never mind rights or leverage, do they care nothing about the working relationship with their employees? The work environment I'm used to is much more collective. If there is a screw-up, it's the team that screwed up, and we fix it together. If it's the same person who causes the team to screw up again and again, it would be a different matter, but when does firing someone over a mistake solve a problem? And if a colleague was let go because his PC started making pacman noises, most of the team would probably quit the same day. I can't even imagine it happening. More likely the boss would joke about it: "Hey, wobbleblob, it sounds like you're not very busy at he moment. In that case I have a nice chore for you"