[MikeD]

Originally Posted by Mark McM

The reporting for this incident started when De Gendt asked on social media if anybody saw what he might have run over, because he himself didn't see anything on the road that he might have hit. As far as has been reported, no one else saw anything that he could have hit. The hypothesis that he hit a rock is just that - there is no eyewitness evidence of a rock, nor any definitive evidence at all that he hit something. It is entirely possible that the existence of the mystery rock is just a convenience for those who would be inconvenienced if the rock didn't exist. (Also note that rims break more easily after tire has flatted or blown off, so the fact that the rim broke is no evidence that the tire didn't blow-off first.)

So no, there is no obviousness of the cause of the failure. And may never be.

We haven't seen the tire. Maybe there was a witness mark on it from the alleged rock? Vittoria said it was a rock.