With regard to the single lane reversing and putting side lights on, I don't think I'd go that far. I'd probably be more inclined to start aggressively flashing my full beams whilst leaning on the horn to let them know I've taken the decision not to give way.
@Revol there's the definitive answer then. I must be honest, I wasn't aware of my obligation to pedestrians etc too. So their frantic hand gestures as I pass weren't them waving me through after all :/
