As far as I know, the woman attacked him and his colleagues personally multiple times, she is a threat to them, they are raising awareness about what is happening and calling for action, they are declaring in a public way that they will not do businness with anyone that supports them.

It's not "encouraging a mob" if someone say "Hey, these companies are advertising with bigots and racists, let's do a boycott to show them that we will not tolerate this".

What you are saying is that they should "shut up and dribble"? Stay quiet with their heads low while they are being constantly attacked?

Calling for a boycott when you don't agree with someone is pretty far from "encouraging a mob" as you put.