Ewan crossed the line first in Strathalbyn, but appeared to use his head several times in the closing few hundred metres as he fought with Jasper Philipsen (UAE Team Emirates) for position. The Australian came over the line with Philipsen in second and Peter Sagan (Bora-Hansgrohe) in third, but minutes later Ewan was relegated to last place in the lead group by the race jury and Philipsen was handed the stage victory.
Lotto Soudal attempted to overturn the decision, but were told that the verdict was final. It's still unclear if a rival team or rider made an official complaint or if the race jury acted first.
Aerts met with the race officials for several minutes, even after Philipsen was awarded the stage win and had been presented on the podium. By this point, a disconsolate Ewan had entered the Lotto Soudal team bus without talking. His teammates looked stunned with the decision but appeared to offer their support as the Australian made his way to the back of the bus.
"It's unfair to me," Aerts told the media after the race jury had made their decision.
"I went with the jury to see the helicopter images because they said that Philipsen was on Sagan's wheel, but I disagreed and we saw that it was Ewan on Sagan's wheel. Philipsen came underneath to get Viviani's wheel. After the turn, Sagan passes again to get Viviani's wheel with Ewan. Philipsen tries to get between Ewan and Sagan, and of course to protect himself from going into the barriers, he uses his head. He said to me, 'What could I do to stay upright? I couldn't use my hands.' I find it very light."
UCI regulation 2.12.007, article 5.1, which was applied in Ewan's case, states: Deviation from the chosen line that obstructs or endangers another rider or irregular sprint (including pulling the jersey or saddle of another rider, intimidation or threat, blow from the head, knee, elbow, shoulder, hand, etc.).
Aerts argued that Ewan was merely defending himself and his position within the peloton.
"Head-butts look spectacular, but if they can't use their hands then they have to use something else. It's a heavy decision for a light thing to do, actually. That's my opinion. I asked if there's a chance to appeal, but was told no. It's definitive."
The stage was also marred by a crash involving race leader Patrick Bevin inside the final kilometres. Bevin was down on the ground for just a few seconds but was forced into a frantic chase. He took a long tow from his team car and made it back to the bunch eventually before being taken to hospital immediately for checks.
At the finish, before news of Ewan's relegation was made public, several teams appeared to debate whether Bevin's pursuit and help from the team car should have stood. Cyclingnews will have more on that story as it develops, but there were no sanctions from the race jury and Bevin retains his race lead.