In OpenStreetMap terminology, a "way" can be anything that should be shown as a line on a map, for example a road, a river, a railway. The "way" you linked to (grey on the map) is a actually a wall. The fire escape you mention (red in the map, next to the wall) is also a way but there is no connection to West Port, so there is no danger that pedestrians will be routed along it. There is also a gate mapped where it connects to Kong's Stables Lane. So maybe it's fine as it is? Or we could add access = no to the fire escape make it clear that the general public is not allowed to go there?