I think the most underrated thing that happened yesterday, and brought big consequences, was Van Aert crashing at the beginning of the stage. Since his crash, he was never able to move to the front of the peloton with Roglič and Vingegaard where he needed to be.
If he is at the front with Roglic and Laporte when Vingegaard has his mechanical, he probably never goes back to the Vingegaard group but stays in front of Roglic and guides him through the cobbled sectors. This probably means better position for Roglic and maybe they avoid the crash.
But if you think about it...how unfortunate they (Rogla especially) were yesterday, it almost hurts. Every stage, stage 5 up to that roundabout included, the team was doing an excellent job avoiding crashes by accelerating before going into tricky stretches of road, be it before a roundabout, before difficult turns, before there was road forniture ahead, before cobbled sectors,... One of the few times they didn't do that, because they didn't have the numbers and another team anticipated them, a freak accident happens and Roglic's Tour dreams are basically over in a second (this year). So so very unlucky...