Lance Armstrong has led the defence of Peter Sagan, who was disqualified from the Tour de France after being accused of causing the crash that ended Mark Cavendish's tournament. The Slovakian rider came together with Cavendish in the twilight of stage four on Tuesday (4 July), leading to the 30-time Tour stage winner falling, and has been removed from the race by the UCI for his involvement in the incident.

Cavendish accused Sagan, who is chasing a record-equalling sixth green jersey as the leading sprinter, of elbowing him into the barrier during the bunch sprint, which caused him to collide with other riders. The Briton suffered a broken shoulder in the episode and has been forced to withdraw from the race – but the debate regarding Sagan's removal continues.

Race commission president Philippe Marien alleged that the 27-year-old Sagan "endangered some of his colleagues seriously" in a sprint which was won by Frenchman Arnaud Demare. Sagan was initially docked 30 seconds and 80 points but an appeal from Cavendish's Dimension Data team led to the increased punishment which has sparked outrage from the cycling community.

Disgraced American cyclist Armstrong, a former seven-time winner of the Tour de France until he was stripped of his titles after admitting to years of systematic doping, is among those to question the decision. "I'm surprised this doesn't happen more often," he said on the Stages podcast.

"For me the elbow came after [Cavendish fell]. Cavendish was already on his way to the ground. It would be another thing if the elbow caused him to crash. I'm 100% sure that elbow did not cause the crash. Is [Sagan] he trying to get his balance? That's the big discussion, that's the big debate."

Sagan's Bora-Hansgrohe team are unable to officially appeal the verdict but have objected to the ruling made by the UCI panel in the hope the decision could be overturned. Geraint Thomas, who also crashed late on in an otherwise undramatic stage, retained his 12-second lead in the general classification ahead of defending champion and fellow Briton Chris Froome.