For all the complaints about 20 seconds not being enough, I wonder if any of this has to do with Froome being so far ahead in the GC. If he started the day only 8 seconds up would a 20 second penalty then seem to be enough? What would be an appropriate penalty to be given uniformly across all riders in any situation who made the same rule infraction?
Also, does anybody know the reason for this rule? Is it to create a more even competitive level? Or is it perhaps to keep team cars from rushing up to in the last 20km and getting in the way of riders trying to make moves for the finish?