I would slow down and anticipate your actions by maintaining a stopping distance and suitable speed between me and the vehicle in front, including while it is overtaking, the driver, if trying to force an accident, would have to actually hit me rather than I hit him. As the Highway Code you quote says, slow down if necessary to allow the vehicle to pass. I am aware of the fact that the car overtaking may well suddenly stop or cut me up, so I take appropriate measures to avoid such.
Which sounds like a perfectly reasonable and safe approach to take, but you can't say that doing this will ensure you never go into the back of the overtaking car. It appeared above as if you are trying to say that it will ALWAYS be the persons behind fault no matter the circumstances. During the overtake there will become a point where they are mere inches in front of you (whether on your side of the road or the other) and if they're car can stop in a shorter distance than yours then you are going to hit them.
But then some people are idiots who want to try and cause accidents, of course your approach would be appropriate in 99% of circumstances and if people were decent enough to not commit fraud it wouldn't be an issue.
I think cyclists sometimes don't realise how small they are compared to a car and therefore how easy it would be to be in a blind spot. It is possible he was cycling along next to the car near its back door thinking he was visible, when he likely wasn't and the drivers excuse of 'oh sorry I didn't see you' could have been very genuine.
It isn't just about trying to predict what others are going to do, but making sure you are in a position to be seen on the road as well as avoid issues as far as possible.
edit: had originally read the article as the audi pulling in while overtaking, which would be a hard thing to try and prevent - but it appears more like the cyclist was just following when he accelerated and then pulled over. Hard to say one way or the other tbh without all the facts but with more information it could easily be either party at fault.
The 2 scenarios I can see are:
1. Cyclist is following audi, audi accelerates and then pulls over. Cyclist does not expect this and does not stop in time. Cyclist is at fault even though audi behaviour may have been irregular or even dangerous.
2. Audi driver overtook cyclist, then broke suddenly in front of or alongside the cyclist and hit him in the process. Driver is at fault for driving into the cyclist rather than getting hit by.
Not that fault is the objective of the campaign, it is the fact the driver committed the offence of leaving the scene of an accident without giving details as has been said above.