RUBBISH!
I pointed out to you before that primary position is about keeping you safe and not the needs of other road users to get where they need to as quickly as possible. For example, if you are going up a steep hill and there is a pinch point approaching, do you a. keep in a secondar position but risk getting squashed and knocked over b. take a primary position and force other road users to slow down whilst you make your way through the hazard? Being excluded from riding in a safe position because you cycle too slowly is RIDICULOUS, espcailly from a cycling trainer.
I agree that staying in a primary position where it is not required can aggrovate other road users and is not advised BUT i don't see in this video where that happens. There are parked cars on either side of the road, the road narrows, the lane narrows, there is on coming traffic. The only safe place for the van driver to overtake is when he does so, and he would have got no further if he overtook sooner. I don't see the problem with him holding the position he does for the length of time he does.