Is 72-hour visa free applicable for this route: SIN-HKG-SHA-HKG-YVR?

If my friend from the US is flying from Singapore to Hong Kong on 16Feb, then Hong Kong to Shanghai on 20Feb arriving SHA at 12:20 & departs SHA/PVG on 23Feb at 13:20 back to Hong Kong, before returning to Vancouver on 27Feb, would he qualify for the 72 hrs free transit?
OR must he fly straight from Singapore to Shanghai (transit in HKG few hrs) on say 16Feb, then depart SHA back to HKG on 19Feb in order to qualify for 72hrs free transit?
Thanks!