#5 that may not be the case. She may have slapped the boss in response to being fired. The reason for her being fired may have very well provoked her to do it.
Before the FML was edited by the staff it only said "I can really explain the slap I gave him, though." It was changed just a couple of hours later. That is why #1 posted that question.
#2 There's a thing called a work record. All he has to do is enter in that she was a lousy worker or ANYTHING like that, and it'll follow her FOR THE REST OF HER LIFE.