First, the yellow: in Alberta, if you are facing a yellow light, you must stop your vehicle if you can do so safely. If not, only then can you proceed through a yellow. The yellow isn't "go if you want" or the ever-popular "speed up and go", it's "clear the intersection, otherwise stop if you can". Other provinces may be different.
On not pulling over right away: again, in Alberta, you are obligated to pull off the road and stop if you see the lights activated on a police car, fire truck or ambulance, either in front or behind you. If the cop wanted to get him for not stopping specifically for his own vehicle (i.e. trying to run away from the police), then he would have charged him with a different offence, likely something under the Criminal Code. From what I see, Peter The Hapless was charged with the more generic "not stopping for an emergency vehicle" offence.