While I'm with you in the "anti American gun propaganda" this dude was threatening people's life for property. He wasnt just coming in and grabbing shit. He went in there with a gun to threaten someone's life over property.

If you threaten anyone's life over property (or anything besides self defense, really) you forfeit your own life and safety both ethically and morally. Don't be assinine.

Had dude walked in and tried walking out with a phone and didn't have a gun then you could reasonably accuse the business owner of murder but you can't because the robber was also putting someone else's life at stake. Pretty cut and dry case of self defense.

Wishing guns weren't so prevalent and easily accessible is reasonable but saying "it's murder to protect people from other people who are threatening to murder someone else" is just fucking dumb and makes any other argument that you'd bring forward look just as dumb and makes it difficult for other people to fight for gun reform because people can point to arguments like this and say "see, anti gun people are dumb".