If I were there as the father of a family, I’d not have taken that kind of chance because it could easily get my family killed. Call me a wuss if you wish, but my first responsibility is to them, not the other family a couple of rows up.
In addition, this appears to be the kind of scenario where it would be difficult to get a good shot at him without hitting a bystander, so I’m not sure being armed would have helped much.
I take this one further, even if I am alone without my family, as the father of two young boys, I am far less likely to risk my life than I used to be. I dont know what I would have done myself, its easy to sit here and imagine what goes on, but unless you have been there, you have no idea what its really like.