This episode was an (almost) identical remake of one entitled "The Silent Witness" from the 1963 black and white Littlest Hobo series. The one glaring difference was that the hit-and-run victim dies in the 1963 version, but lives in the 1979 incarnation.
While there are obvious indications that the episode takes place in Canada, the Gold Cross ambulance used is mainly used in the U.S. (Utah & Wisconsin to be exact). No explanation why a Gold Cross vehicle and not the standard Red Cross ambulance would be used.
In the scene where the hit and run victim is being loaded into the ambulance, one extra can clearly been seen sitting on a chair; making it look like someone had brought a chair to watch a crime scene.