Bek's argument makes no sense. He writes that he had to temporarily prevent overtaking by the motorist behind him. I saw no reason why that motorist had insufficient sight distance to determine whether it was sufficient for a safe overtaking.

For whatever reason, Bek refuses to consider the real issue, which is a lane position that will discourage motorists from trying to squeeze between the cyclist and traffic in the adjacent lane. Of course, as long as there is no traffic in that adjacent lane, then there is no reason to move left, but when there is traffic in that lane the cyclist should be sufficiently left to discourage dangerous overtaking. So Bek's argument that he saw no reason for a leftwards position boils down, on the road in question, to staying right until you see opposing direction traffic approaching, and then move left to prevent a faster motorist from trying to squeeze through the gap between you and it.