The flip side of the coin....
If the dead man had a firearm and shot and killed the outraged, violent father, would everyone on this thread agree that the dead man was lawfully exercising his legal rights under “Stand Your Ground” laws?
The dead man had a criminal history of shoplifting, trespassing and obstructing police, if he had a gun it's likely he would be in the commission of three more felonies.
Harris admitted to punching the dead man but said the man swung at him first, so it may be that the dead man had no right to "Stand His Ground" and use the gun he was proscribed from possessing.
It also may be that the dead man was unfortunate enough to lose the fight that he started.
It may again also be that the recent criminal acts of the dead man against Mr. Harris' Daughter and Mr. Harris himself, so angered Mr. Harris that he could not discern when the dead man was no longer a threat.
Finally, how would I know what "Everyone on this thread" would agree to?
From what I read in the article, I would. We don't know the guy was a pedophile. We don't know the configuration of the rest room(s). As one other person pointed out, he might not have known the girl was in there. He might have thought the door was stuck and the stall was empty.
We do know that the rest of the incident took place outside the store. The father drove over to the guy and got out of the car to confront him. The father wasn't defending or protecting anyone.