If you listen to some of the pundits and ex pro's, professional cycling is 'as clean as it's ever been' these days.Quite possibly, though it’s been a long, long time (if ever) since the Tour was ridden on bread and water alone. I mean it’s a superhuman undertaking to do that for 3 weeks, day after day. I find you have to ‘suspend your disbelief’ to enjoy pro cycling tbh.
It's sad really that the reputation of a sport is still suffering from what went on from the early days of the Tour right the way through to probably 2010, possibly beyond and there will always be that niggling doubt.
Having said that, some of these strange performances could be down to something like not having a good night's sleep, or an upset stomach. Something like that can play havoc with a riders pre-race fuelling strategy and would certainly mean they weren't at there best, especially on the climb's. Let's face it, they've not really had the best prep, and they've had to peak later in their training cycle this year.