I can tell you that for a large period of time during the first few weeks, it was a very volatile and agitated situation out on the road. Police officers have discretion in any situation when they feel intervention will worsen the situation or make it more violent for people around or for themselves if they're going to be putting themselves or other members of the public at risk—
Evidence of meeting #17 for Declaration of Emergency in the 44th Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was emergencies.
A video is available from Parliament.