It was a quick decision from the Union Cycliste International (UCI) commissaires to relegate Sagan for a 'dangerous sprint' after vision from the overhead pictures of the sprint clearly showed Sagan forcing van Aert aside with his head to create a path late in the sprint for stage honours.
Sagan first passed Clement Venturini (AG2R La Mondiale) close alongside the barriers before trying the same thing with van Aert. The gap between van Aert and the barriers was too tight however, and Sagan used his head on van Aert to clear some more space.
The move allowed him to pass van Aert and claim second on the line, behind Caleb Ewan (Lotto Soudal) but just ahead of green jersey rival Sam Bennett (Deceuninck-QuickStep).
“I think it’s not done to do it like that, actually,” Van Aert said after the finish. “In my opinion, I sprinted in a completely straight line, I started complete on the right on the barriers, and he just tried to create space for himself, and for me, he's not allowed to do that. I think it’s already dangerous enough.
“I was really surprised and shocked at the moment I felt something. I was making a maximum effort, so I was really scared.”
The Belgian star was then asked whether he could have placed higher on the stage without Sagan’s interference.
“Higher? Of course, but I don’t know if it was enough to win,' Van Aert said. "The only opportunity I had was when there was some space on the right and that’s why I went a bit too early. It would never have been perfect but to end like this – it’s frustrating.”
Sagan was later relegated by the commissaires' panel to last place in the group, moving Bennett and van Aert up one spot. Van Aert's immediate response to Sagan after the line involved some abusive language and gestures, though he had calmed down a bit by the time he talked to reporters.
“[I was] so shocked and angry I didn’t use a very nice word," van Aert said. "Afterwards I tried to say to him that it isn’t done like that and I didn’t like what he was doing. The only thing that came back was strong words, so it was hard to have a conversation.”
Van Aert was dismissive of suggestions that Sagan’s renowned bike handling abilities are such that he perhaps believes he can go through spaces in the peloton that aren’t there.
“That’s a weird way of thinking, there wasn’t a gap,” Van Aert said. “And if you use your elbows to create one, that’s completely against the rules. It’s not reasonable, and it’s not done.”
The Jumbo-Visma rider was backed up by his team leader, yellow-jersey wearer Primož Roglič, who supported the UCI commissaire's decision.
“I just saw the sprint and I think it’s the right decision [to relegate Sagan],” Roglič said. “The sprinters are quite different to the rest of us, they are really crazy guys, fighting for those places and fighting for the sprint, but it still needs to be fair. It’s the right decision.”
The Tour de France continues tonight with Stage 12, the longest of this year’s race, a 218-kilometre course similar to an Ardennes classic from Chauvigny to Sarran. Watch the race on the SBS ŠKODA Tour Tracker from 7.40pm AEST, with television coverage starting from 9.30 AEST on SBS HD.