Have you noticed there seems to be little interest by the RCMP and the corporate media to investigate how a military operation facing unarmed people could leave five vehicles unattended long enough for someone to set all five on fire and get away completely? With all that military technology? You may rest assured that one of two things will happen. A "perpetrator" will be found who will profess support for the indigenous cause, or no one will be "found" and the incident will be forgotten, the photos having served their purpose of providing and excuse to use violence.
Most likely the collaborator was someone who has been associated with #idlenomore and is in trouble with the law like this person: https://twitter.com/PerJa_7/status/391074090687021056/photo/1 you can read more about him here and here.