It actually happened at last yesterday, going down a slight hill into the town centre, it is a 40 limit, and I was doing 40, in primary with the flow of traffic, holding no one up, at the bottom is a set of lights as it goes onto the ring road around the town centre, the road splits into two lanes, I take the right lane to turn right, the car behind takes the left to go straight on. While we wait at the lights the driver winds his window down and says I should have been on the shared path, I ask if he means the one with all the school kids on, he says yes, I then ask him how fast I was going, he says 40 and then the look of realisation washes over his face, "my bad" he says, gives me the thumbs up and puts his window up and looks ahead with a kind of grimace on his face. I am pretty sure I saw him later when I was crawling up a big hill at 5mph in the bus lane, still passing the line of traffic however.