A link to whatever story OP was talking about would have been nice. Here's one from Yahoo that includes accounts from other witnesses:
https://www.yahoo.com/travel/family-...150654020.html
If a Knee Defender was in use, then that should be automatic game over, but I didn't see any mention of it in 2 stories I read.
It sounds like the FA is in the wrong here, but there's a question of whether the FA went on the PA to call the family "animals" after they deboarded.