Firstly, firing the intern doesn't make sense - it was a mistake waiting to happen and he just happened to do it at the wrong time. Secondly, the punishment meted out should be: 1. Proportional to the degree of carelessness (in this case not that much since he accidentally hit a wrong key adjacent to the right one, didn't mow down anybody while driving drunk) 2. Inversely proportional to the likelihood of the error (…
I think you're wrong to ignore the consequences of the actions as an input to the punishment. A small amount of unintentional carelessness that causes huge damage could still be punished. One could argue that a certain degree of mindfulness in critical situations is a job requirement, and casually making a careless -- though unintended -- mistake demonstrates a lack of mindfulness indicating that the person is not pr…
In this situation, the secretary playing the game is just as culpable as the intern, which is to say, not really responsible.