Speaking immediately after the stage Van Aert say that he and Sagan exchanged angry words, which continued as the riders slowed down to a stop.
Furious Van Aert makes it VERY clear what he thinks of Sagan after dangerous sprint finish
Analysing the incident on The Breakaway after the stage, Sean Kelly said that the decision to relegate Sagan was totally justified.
"It’s a crazy one what he’s done there," Kelly said. "He knows, he’s been around for a long time, he’s not a new guy, a young guy eager to just get a stage victory.
"He’s been in these sprints and you saw it with (Mark) Cavendish in the same situation.
He knows the moment you do that with your head, if you touch your head on the shoulder of a rider, you’re definitely going to be relegated and lose all points. The win was there and these guys will do anything to get the win.
"That was something you could get away with in our day, you didn’t have these overhead camera angles so you could get away with a lot more"
Bradley Wiggins agreed that it was the correct decision, saying it was the choice of line that was the risk by Sagan.
Wiggins says Sagan's choice of line was reason for dangerous situation
"He was coming up with momentum, had it been a straight sprint he probably had the momentum to come through and win," Wiggins said. "We’ve seen him get better and better each day, he’s actually finding his legs now.
But he ran the risk of that gap ever so slightly closing between the barrier and the rider and that’s the risk he ran by going up the inside. That’s sprinting. He was in the opposite position a few years ago with Cavendish.
"Had he been Van Aert and had Van Aert done that to him I’m sure he would have been ok with the disqualification (relegation) so he has to accept it.
"And the big winner today is Sam Bennett in terms of the points he’s gained in that competition. It’s a shame for Sagan in that sense but there’s a valid reason why he’s been relegated."
'There's the shove!' Analysis of the four-way photo finish that saw Sagan penalised
Sagan was disqualified from the Tour de France in 2017 for elbowing Mark Cavendish into the barriers.