They are acting as a group. If anyone within the group had stopped the others, I would agree with you in principal, even if not fact. But they didn't, they stood by and watched or cheered. They enabled.
Literally throwing shit is not peaceful protest.
Urinating on a war memorial is not peaceful protest.
Blocking access for ambulances - potentially causing significant harm or death - is not peaceful protest.
Ottawa has peaceful protests all the time - this is not that.