Humpback Rd and Hwy 14 is about 1.3km from the point where the two lanes merge into one (via Google Maps distance measurement). No one is slowing down from 80 to 60 with over a kilometre to go. The fact that most drivers aren't slowing down to 60 anyway notwithstanding.
Interesting theory though.
EDIT: I forgot that the keep right to pass rule is regardless of actual speed. If some dick is rocketing up to you at 240km/h in an 80 or better zone you must move right. So even if people are slowing down to the target speed with more that a kilometre to go, they still need to stay right if there is a vehicle behind them.
Again, not saying the SUV driver was right by any stretch of the imagination, just wondering if this wouldn't have happened if the dashcam vehicle had followed the MVA, assuming* they weren't.
* Therefore making an ass out of U and I. Ta da!
Edited by DustMagnet, 25 January 2020 - 08:59 PM.