As you put it, yes. I am not disputing top bike handling skills. But it still stands that pro racers (and not just them) often put safety second to speed. Why would that descending style where you sit on the top tube (conveniently sloping to allow that use to great profit) be ruled as not allowed in pro racing (actually didn't follow that up, but there was talk to that effect it won't be allowed).

But tucking down on the top tube is unsafe for a different reason. But if you get the wobble effect in this position, then you are also screwed.

Her saddle clearly developped strong sideways oscillations, ergo she didn't have it squeezed between legs. I rest my case here.

I recall from two years ago in TDF (I think), one rider went down on flat straight road, for no apparent reason, like he was chopped down. Luckily he took nobody else with him. It looked like his front wheel got turned ninety degrees in a blink... I suppose ^&* happens on bikes engineered to or rather, perhaps, ridden to extremes.

Mind you, it doesn't follow that spending most of your life on a bike, like a pro racers do will somehow give you superior bike handling skills. Else why some would be touted as having poor(er) bike handling skills (usually descending) when compared to other pro racers and its not that they ride the bike any less than others they are compared to (gets noted frequently in race commentary). Many people have those skills like Sagan while not racing bikes at all. BTW I am his fan, in part also because he is almost my countryman.