Not that it matters now, but in the future I wonder how many people will even attempt a last lap passing move because of this terrible ruling.
This is the rule that needs sorting out though.
Of course a drive through penalty can be reversed.
You can work out how long it takes for a car to drive through the pits, deduct that time from the driver's overall time and if the driver ended up getting caught up in traffic, based on the comparative lap times you can easily calculate what position the wrongly punished driver would actually have finished. A half-way competent statistician armed with Excel® could do this easily