Motorized Wheelchair Vs. Vehicle???

is survival of the fittest a thing of the past? or is it just ignorance? or maybe physics that some refuse to acknowledge?

last i checked, collisions involving one object considerably bigger/heavier than the other, the other didn't fair so well... but apparently motorized wheelchairs are exempt from this rule of thumb.

i was driving back to work from the local tim hortons when at a set of lights, said motorized wheelchair (for the remainder of this post will be called: MWC) was in the right-hand lane with it's left signal light on and a car on its left side going straight and the car on the other side of the intersection going straight as well. i think they knew the one car was beside them, but didn't even pay any attention to any other traffic, which there were at least 8 vehicles at that intersection at that time.
well the vehicle next to them goes through the intersection when the light turns green, but then instead of driving into the turning lane, proceeds to cut me and the vehicle on the other side of the light off and didn't even flinch! of course anyone would be too scared to even accidently hit a MWC so everyone just let it happen and no one tapped their horn or anything, myself included. i know the look on my face was disbelief that they actually do this knowing full well how much bigger a vehicle is compared to a MWC and yet still cut at least 2 vehicles off when not even having the right-of-way and didn't batt an eyelash.

do they think they have the right of way just because they have a MWC? or are there infact seperate rules that apply when they are on the road?