And how do you know all this had not already been tried?
How do you know this wasn’t the 10th or 20th time this had happened and nothing had been done, and he was finally just fed up. After all he did tell her this might get him fired.
Very much doubt this was the 1st time, or even the 5th time.
How many times would you put up with this?
It doesn’t matter if it was the tenth time: THE EMPLOYEE SHOULD NOT HAVE POSTED THAT NOTICE ON THE DOOR, PERIOD. I don’t know why you find that acceptable!