Stupid actions from relatively smart people

In the past two days, we've had:

1. a kid who outright defied an adult to the point that she tried to write him up, at which point he defied her even more directly;
2. an adult who lost her temper too much toward the kid who defied her (can't go into detail);
3. a cafeteria worker who took a lunch tray from a kid because he couldn't pay after she had been told several times not to do that because she would get her money some way (this came from the principal) and she did this in front of Eva Herbst (NO one mistreats a kid in front of Eva Herbst);
4. a sub who got snotty with Eva Herbst. (NO one gets snotty with Eva Herbst.)

Notice only one of these bullets is about a kid acting stupid.