Interesting theory. But in many places, it looks to me like things were horribly broken from the beginning. For example the following link, where points that should be on one way are randomly distributed between two ways.

http://tools.geofabrik.de/osmi/?view=multipolygon&lon=-89.93124&lat=30.35450&zoom=17&overlays=invalid_geometry_hull,duplicate_ways,intersections,intersection_lines,ring_not_closed_hull,ring_not_closed,unconnected_end_nodes,touching_inner_rings_hull,touching_inner_rings,role_mismatch_hull,role_mismatch,ways,role_markers,way_end_nodes,way_nodes