So we may have to agree to disagree on this one, as I understand WC you can control the opponent through gravity or through angle or both. Saber fighting as I've learned works using an idea of walking the circle around the opponent, facing the square in the middle and dealing with a single line. These are more or less different ways to work strategy and leverage together.
When the guy in the video turns his back, he is using what i would refer to as circular strategy, moving to the side of the opponent so that the opponent would have to apply his pole cross body to counter (weak angle). He is attempting to take advantage through angle instead of staying straight on and dealing with potential short range mechanics of the pole fighter (from what i remember of YM pole there was some fun stuff for that). Additionally, he can be considered to be blocking the length of the pole with his body, making the pole fighter have to back up or keeping him frozen in medium/short range where a long weapon is not as effective.
I'm not saying it's the only option, I'm just saying I can see a reasonable goal to what he was trying to achieve. looking at the setup, i think walking down the pole could have worked, but would be a challenge to gravity instead of angle. I think the pole guy had more opportunity in that scenario based on the setup.
Also, live/dead side is a common stick/weapon fighting thing from CMA. We use it in Hung Fa Yi WC, I know Hung Gar uses it and I've heard of it in more than a few other places. It's a paradigm for stating how much advantage you have/how much opportunity the opponent has.