With the element of surprise and the dark, the balance of initiative shifts, odds are very good that one father could kill two, starting with the gunman distracted by the show, and the rest would scatter.
Kill them with what? He was unarmed. This is real life not some action movie.
Blaming the father is wrong. Blame the thugs, and the Liberals that coddle them and who strip law abiding citizens of the God given right to protect themselves and their families.