Sagan and Jesus Esteban, the in-race moto driver who inadvertently collided with the rider late on stage eight of the 2015 race, met and made up during the 2018 Vuelta a España's rest day.
The Bora-Hansgrohe rider gave Esteban a signed world champion's jersey, whilst Esteban gifted Sagan with the front windscreen of the motorbike which he had been driving that day and which was broken when he collided with the rider.
According to a Tinkoff-Saxo team press release at the time, as a result of the accident, Sagan suffered wounds and burns of first and second degree on the left side of his body, from the hip to the lower leg. He also had a contusion on his left forearm with an intra-muscular haematoma.
His shorts ripped to shreds, revealing his injuries, the then Tinkoff-Saxo rider punched the Vuelta medical car, gestured vehemently at the race motorbike, then appeared to kick his own bike. Fined 300 Swiss Francs by the commissaires for his actions, Sagan finished the stage but then quit the Vuelta that evening.
Esteban was expelled from the race, while the organisation offered an apology. Although the team threatened legal action, it did not materialize.
Three years on, when the two met after Bora-Hansgrohe's rest-day training ride, under much more relaxed circumstances, Sagan put the tumultuous events of that year's Vuelta in a bigger perspective, arguing that every cloud has a silver - or in his case, rainbow-coloured - lining.
According to Spanish news agency EFE, Sagan told the driver: "Thanks to that crash, I became world champion, so I have to thank you.
"The crash meant I left the race, but it wasn't so bad because I had won a stage and I was going to quit soon anyway. From that day onwards, my road towards three World Championships began."