Just a thought about the whole BMC vs. Movistar (helmet off vs. push) thing.
While it perhaps was debatable whether Rojas' push gave Movistar any advantage, I'd like to see anyone try to argue that TJ taking his helmet off gave him any advange. In fact; if the peloton had suddenly started to go full-gass while TJ was fiddling with his helmet, well... I think I know who would have lost time.
Of course there's the whole safety issue, there's a reason helmet use is mandatory. However, I can't help but wonder if that rule about riders being DSQed if they take their helmets off during a race was created back when the riders weren't perhaps 100% onboard with the whole mandatory helmet use thing, and after the - brief? - period during which riders could take their helmets off if a stage ended with a MTF, to remind people that "No, you can't do that anymore." Nowadays, otoh, I don't think anyone would try to argue against helmet use.
What caused TJ to take his helmet off? I don't think he just randomly decided to fiddle with the straps because he was bored. No, I suppose there was an issue with the straps, and issue which - perhaps - could have actually lessened the protectiveness of the helmet. He then picked the best time - while everyone was riding relatively easily - to fix it.