I don't argue anyone's right to protest, but there is a time and place.  Doing so during a national anthem, any countrys, is disrespectful.  The knee drop  was  done to intentionally provoke a response.  It was IMO the wrong time.  Just like an inappropriate time to protest would be during a funeral, or a  baptism, or a Change of Command ceremony.  You have to give respect to get it, and not just when it's convenient for you or your cause.  Just because you can do something doesn't mean you should.