Another, '...the driver isn't aware, so it's not their fault...' defence and then victim blaming? They're weak arguments and need to be called out whenever they're regurgitated.
The fact is, the vast majority of safe overtakes require the vehicle to cross the centre white line. It doesn't matter whether you're crossing this line by 50cm or 2m, you're still crossing it and shouldn't do so if oncoming traffic, for example, prevents the safe execution of the manoeuvre. So it doesn't usually matter if there are multiple cyclists side by side, you still have to cross the white line and shouldn't do so if it's not safe (as per the HC and multiple statements to this effect by police forces on social media). You should not eat into the passing 'safety' zone just because there's a car/obstacle coming the other way/ahead of you! I see it all the time, where the oncoming driver has to take evasive action and pull over to the side to allow an overtaking car to pass (this is against the HC).
The flip side of this is the motorist passing too close to the cyclist and even making contact, which has happened to me many times over the years. I've been knocked into the kerb and off my bike more than once. The motorists have never stopped to check on me. Some have slowed down for their passengers to hurl abuse or objects at me. Pedestrians have walked on by, not wanting to get involved. Imagine that being a car on car incident?
It's also never about proving a point. It's about protecting one's life. Literally. Cyclists have been de-humanised. If motorists had to put up with the same treatment and dangers as cyclists on a daily basis, there would be a massive nationwide campaign to stop it.
