In a person-pushing-bicycle combination, there are two components: the person, who has the character of a pedestrian, and the bicycle, which has the character of a vehicle. The question is, in legal terms, which of the two contradictory categories applies to the combo? Pedestrian, in which the actions of the cyclist in the vid are legal, or vehicle, in which case they are not? C v. B says that when the person starts as a pedestrian, pushing the bike on the pavement, and ends likewise as a pedestrian on a pavement, it is sensible to treat them as a pedestrian even when they're on the carriageway. It seems to me (though I am not setting myself up as an expert) that the converse is also sensible: when they start the manoeuvre as a vehicle, on the carriageway, and finish it once again as a vehicle on the carriageway, and remain on the carriageway throughout, their predominant character during the ambiguous pushing-the-bike phase is also that of a vehicle.