What I propose, gentlemen, is that both parties displayed spectacular lack of common sense, but while Aggro Yob's decision to eject himself from the van in the middle of the road was indefensible, the Spandex Vloggin Ninja should actually sit down and deeply reflect on stupidity of his behaviour if he wants to continue unlocking Lance Armstrong streetracer achievements for the next 37 years for what he did, shouted and performed there, on his own video was ultimate, bottomless stupidity.
Unfortunately its simply misinterpretation, this isn't a camera with zoom looking ahead, all the pictures you showed, none of them show the whole van, NONE of them. Meaning the van wasn't past the bike at any point.
Firstly coming up to a junction where you intend to turn, with traffic ahead, you should never attempt a passing manouvre at any stage, till the corner is delt with. Secondly, he never passes the corner, thirdly the VAN slows down because he's approaching the corner, thats what happens with cars/vans, bikes are more manouvreable, he didn't speed up, he simply wasn't required to slow down as much for the corner.
Bike and van, side by side, bike has the inside lane, van assumes bike will simply slow down and let him pass then stay out the way. One of the reasons to ride a bike in traffic is the fact you can pass cars as they are slower at many points.
Anyway, the van has never overtaken fully at any point, then on the next road he fails to leave clearance. When you overtake another car, its the overtaking cars job to speed up, and get back infront of the vehicle its overtaking SAFELY with enough space. You don't pass a car, ever, and just turn in forcing the other car to break to avoid a collision, you speed up, you pass the car completely then you go on another amount of distance so you can turn back in without effecting the vehicle.
The van driver didn't get a single thing right, and after all that decided to turn into the bike, they stop when HE HIT THE BIKE, then assault the guy.
Yes, the bike could have slowed down at any point, so what, you could slow down and let every single vehicle behind you pass aswell, theres no legal requirement to do this, and judging by the traffic ahead the van has no where to go and the bike will like on the previous corner, be much faster through the traffic.
Even if he HAD passed the bike, the bike would have re-overtaken him at the corner where he is much faster, and the van would be attempting a new manouvre on the next road.