It led to the first withdrawal of the race as Jasha Sütterlin of Team DSM was forced to pull out with an injury.
The 2012 Tour de France winner Bradley Wiggins said he had no sympathy for the fan involved.
"They're part and parcel of the spectacle of the Tour de France," he told Eurosport. "And this year, in particular, being able to come back onto the route and watch it. I don't know how you police it."
The crash affected the race massively, with it taking almost 25 kilometers for the peloton to fully regroup.