Professional and amateur sports events around the world have dealt with streakers running on the field forever without violence. Its not like they are wielding a hammer obvious out to attack someone. Or a taser if you will.
Police should be trained to de-eskalate nonviolent situations without using violence and in other countries they are. I know, the US police force is not and that is a shame on them, but it doesn't justify to shoot or electrocute someone in the back.