The minibus driver did take defensive action by applying the brakes. In the event of a collision, in this instance, the car WOULD be 100% at fault. There is no other way to see it. The law and highway code are black and white on this. Being courteous is not part of law. Being aware is. The minibus driver demonstrated this by applying the brakes to try to avoid a collision (whether his actions did this or not is irrelevant). He may even have been gently slowing suspecting the car may do what it did?
The car had a choice, in fact a number of them. At 20mph, the car could have accelerated slightly. If there was no room to do this, that only damns the car even more, as they were not reading the road! I am guessing too, that there were vehicles behind the minibus, which could be why the minibus driver did not slow. The minibus driver may have lost sight of the vehicle behind and therefore been concerned of a rear end collision . If there were no vehicles behind the minibus, the car could have slowed to slot in behind, again damning the car driver further.
Both drivers had an opportunity, both failed to use it, but the car driver forced a decision on the minibus (to slam on the brakes) by using their sense of entitlement. The minibus driver had right of way, the car driver should have respected that and acted accordingly. But as is all too common on the roads nowadays, we have people who have to be in front (occasionally I am guilty of that too, and kick myself after). I find it funny on some youtube videos of collisions, where the (in my view) guilty driver says, did you not see my indicator? errrm did you not see my 40ft fully laden container lorry????
Your situation as I read it, you placed the motorcycle cop in a potentially dangerous position. When letting traffic through, whilst it would not be your fault, you could should have been aware of the vehicles behind you in the other lane. The car driver passing in front of you, may not have seen the cop, coming up in the other lane. Here, you are forcing another vehicle to make a decision on what I imagine to be a straight continuous road, where stopping/slowing would be an unusual action?
The car driver was already stopped, so them waiting a few more seconds is not hindering anyone else, and everyone knows then what each other is thinking. In a clear road behind you, it would be fine, courteous and a nice thing to do. But in a road where there were vehicles behind it would be potentially dangerous. At 10 seconds in,
THIS video shows what I mean.
If I am in a single lane of traffic, and i see I will have to slow, I will happily let people out if they are waiting. However, if there is another lane to my side, I will still do it, but only if I make eye contact with the driver crossing. This way I can alert them of vehicles coming in the other lane. But if the traffic is moving, even if I am the only person on the road, I will not let them cross, as they can wait a few seconds until I pass, and they wont have to wonder if I am slowing to let them cross, or just adjusting my pace.
We are now no longer relying on rights of way, on the road, and now second guessing others (sometimes biased by their choice of vehicles too
).
(and yes you are correct, calling a collision an accident implies blame, which the police are not there to do, they gather the evidence for a court to decide that)