Keep left is more a rider etiquette sort of thing than a rule. It's the kind of etiquette that helps avoid collisions and other flapjack related mishaps.
Riding appropriately for the conditions and slowing to avoid someone enjoying a flapjack would also be etiquette.
Calling someone a dick in public is just poor form, unless you spit at them and grab you crotch.
Pedestrians can walk wherever they like on a shared path, so his 'keep left' admonishment was somewhat out of order. In fact pedestrians retain the right to walk anywhere on a segregated path (i.e the ones with a painted solid line down the middle, a la London Fields) as well.
Keep left is more a rider etiquette sort of thing than a rule. It's the kind of etiquette that helps avoid collisions and other flapjack related mishaps.
Riding appropriately for the conditions and slowing to avoid someone enjoying a flapjack would also be etiquette.
Calling someone a dick in public is just poor form, unless you spit at them and grab you crotch.