I take it that was somewhere outside St Etienne from the 42 plate on one of the cars at the finish. (I haven't yet checked on maps!) In which case it was quite probably more than comfortably hot which explains why the author had less power than he was expecting (looks warm to me, summers are hot in that part of the world). I have only watched on the phone so far, going to have to see it on a bigger screen. The descent was not bad either.
Sooner them than me!!