That's not correct Geoff. Did you actually watch the race.?
There was a discussion over the radio (which was aired)where the race director stated that NO lapped cars would be allowed to un lap themselves before the pace car came in. Then, after pressure from Red Bull, the race director changed his tune and said that the 5 cars between Lewis and Max would be allowed to pass. This is the point that MB were furious about because for the sake of an unfair last lap the director hung Lewis out to dry.
After a crash like the one that happened, Mercedes were experienced enough to know that there was not a recovery vehicle close enough to remove the scrapped car quick enough and for the lapped cars to un lap before the race finished under SC conditions.