With out examples it is difficult to tailor my reply. I can provide my own cases though when I did just what I think the OP is referring to. As an individual in authority there have been plenty of times I did not accept an excuse and held the person accountable accordingly - usually when they have been grossly irresponsible or unreliable. For instance, showing up to work with a hangover; it is not my fault you were up late on a work night, you still have a job to perform.