Vittel - British sprint great Mark Cavendish demanded an explanation from Peter Sagan after he was elbowed into the barriers at the end of Tuesday's Tour de France fourth stage.
Cavendish was following the wheel of eventual stage winner Arnaud Demare of France when world champion Sagan jutted out an elbow, knocking the Briton into the barriers where he came crashing down to the ground, just 100 metres form the finish line.
Two riders following were unable to avoid Cavendish and hit him as they somersaulted over the top of him.
Cavendish, 31, was treated by medical staff before finishing the stage but he had his hand bandaged and was wearing a sling as he left by ambulance to go to hospital.
"Injury-wise I'm going to go and get it checked out," he told a scrum of reporters outside his Dimension Data team bus.
"I will definitely need stitches in this finger, it's bleeding a lot.
"With the shoulder, it might be something to do with a previous injury, it's sat backwards so I'm not sure if I've done something to the ligament.
"I'm not a doctor but from the feelings I'm not optimistic."
But Cavendish said Sagan had to explain his actions.
"I was just following Demare round, and then Sagan just came over," he added.
"I get on with Peter well but I don't get it. If he came across it's one thing, but the elbow?
"I'm not a fan of him putting his elbow in like that. I get on with Peter, a crash is a crash, but I'd just like to know about the elbow."
Cavendish's sports director at Dimension Data Roger Hammond told journalists: "If I was Sagan, I'd apologise for that."
Cavendish's was the second of two crashes in the final kilometre as riders jostled for position to contest the sprint finish.
Race leader Geraint Thomas was taken down in the first crash, along with around a dozen riders, but he emerged unhurt.
"The crash happened right in front of me, I had nowhere to go really," said Thomas.
"I managed to take off quite a bit of speed, I hit the deck but I'm fine."
It was the second time in three stages that Thomas had been caught up in a crash.
"It's ok, both times I managed to take off quite a bit of speed," he added.
"I'm used to crashing, so it's fine, I'm all ok."
In all the furore of another bunch pile-up, French champion Demare's achievement of becoming the first Frenchman to win a Tour stage in a sprint finish since 2006 was almost lost.
"It's amazing, beating all the best sprinters like that at the Tour de France is something I'd hoped for, for a long time," said Demare.
"Now I've managed it once, I think I can do it again."
His win allowed him to claim the sprinters' green jersey from German Marcel Kittel, winner of Sunday's second stage but who was held up by the first crash and unable to contest the sprint.
Slovak Sagan took second place with Norway's Alexander Kristoff third on the stage.
Sagan's time bonus on the line helped him move up to second overall at seven seconds behind Thomas, with reigning champion Chris Froome, who was held up by the first crash, third at 12sec.
As the crashes happened in the final 3km, those caught up in them had their finish times protected so didn't lose out in that sense.
Sagan, however, may find himself in hot water with the race commission and could be disqualified from the stage.
Earlier, Guillaume van Keirsbulck attacked from the starting gun but unfortunately for him, no-one tried to join him.
It left the 26-year-old to plough a lonely furrow for 190 kilometres.
At one point, 60km into the race, he led by more than 13 minutes but he was caught 17km from the finish.