People who grew up in middle class America probably didn't see street violence on a daily basis. How dangerous it is to even look a someone the wrong way can lead to being beaten, stabbed or shot. The prisons are full of violent men and women, where do you think they were before they landed in prison?

Also, how do think road rage and other angry conflicts end up with someone dead and someone going to prison?

It's easy to see who doesn't want to fight you in most situations so they didn't think much of it when they engaged in their attack of this woman. You never know though. An elderly man killed a road raging young man with a compound bow years ago. I bet he didn't see that coming.

Point being, you pick a fight with the wrong stranger and you may get someone that doesn't back down, it quickly escalates, a gun comes out and you can see how this ends.

99% of people probably probably won't let it escalate.

To answer your question, did they deserve to be shot? Nope. If however, they didn't like an aggressive response and squared up, flexed on them and got in a person's face would THEY try to deescalate what they started? Most likely not. At which point they may be fighting a person who is mentally unstable to begin with, violent and willing to shoot someone.