These are separate issues. Just because this particular shooting may be defensible or just r lawful doesn't mean that people are not going to be upset by, especially in context of everything else going on.
We ought to all be supportive of peaceful protest, and we all ought to condemn violence.
We also ought to be critical of those who manipulate others with it. This includes those who will take one or two examples of violence and use it to dismiss the legitimate protests of thousands of others.
I don't blame Trump for that phenomenon as it has been going on long before he was around. But I DO blame him for not having the character to call that out, just as he would be critical of individual acts of violence.