The consequences of the error matter to the extent that the consequences of the error are predictably extreme.
I'll give an example. I work in an office building with many floors that have exact same layout. One day I was on a floor that wasn't mine, and went to where my desk should be, and tried to sit down. I was shocked, for a moment, to discover my coworkers had all been replaced by strangers. In this case, I made an absentminded mistake of not paying enough attention to my current location - but the consequences were trivial, so the mistake itself is no big deal. Now, on the other hand, suppose while driving down the road, I absentmindedly ignore a red light, plow through an intersection, and kill a family of five. This is also an absent minded mistake, but the predictable consequences of being absent minded while driving are a lot more extreme than being absent minded while walking about an office building.
To apply the logic of my example to the case at hand - imagine that in one scenario an employee is, during a boring moment, cleaning his keyboard with his chat application open. This results in that employee sending a nonsense message to a coworker. Silly mistake, and no big deal. Now, suppose that same employee has the "Missile Alert" app open and decides to clean their keyboard. This is a similar mistake, but with potentially bigger consequences. I think it's fair to treat these two actions differently.