The amount of cycling chops that riders like Chris Froome have is off the scale - they do everything on the bike often while riding at stupidly high speed in a group of cyclists. They eat, drink, p**s (and worse, on occasions), take off arm-warmers and waterproofs, have cuts cleaned and dressed etc etc. Every so often something will go wrong, and this is one example, no matter how experienced you are. I can't believe how nasty and painful-sounding his injuries are; I've broken collar bone, humerus, finger, toe etc (I must stop playing football) but nothing like his range or severity of injuries all incurred at once.
As for the toilet thing... many years ago during a Tour of Italy stage I was in the Linda McCartney team car in role as a cycling journo. And I was bursting for a pee. Handily the team manager/driver (the legendary Sean Yates) needed to go as well. We stop, do our stuff quickly, but the mechanic who was also travelling in the team car couldn't pee on demand so had to hold it in... for a few more hours!!