That is not how it looked at the time, however. Vinokourov’s fall came just as the peloton had closed to within about one minute of the four riders who had broken away 12 miles after the start and had led the stage for more than 90 miles. The cyclists at the front of the pack were riding hard — and then they appeared to start riding a bit harder.

Image A bloodied Alexandre Vinokourov crossed the finish line after losing 1 minute, 20 seconds in the standings. Credit... Eric Lalmand/European Pressphoto Agency

“It’s the last thing you want to see, someone like Vinokourov lose time like that,” said Frank Schleck, a rider for CSC. “We didn’t know it happened until we came to the finish line.”

But if the riders were unaware, they were among the few. Many of the team cars, which follow the riders to help them if they have a flat tire or need a new bike after a crash, have televisions and the team managers watch race coverage. And most of the riders talk to their managers on radios they carry in jersey pockets.

Nevertheless, Marc Biver, the general manager of Astana, said he did not believe that the peloton had tried to take advantage of Vinokourov’s misfortune. He said that because the fall occurred just as the large group of riders was about to catch the breakaway, it was inconceivable that they would slow to allow Vinokourov to catch up.

“I don’t see it as a personal attack against our team,” Biver said. “It’s a logical thing that happened. Maybe I’m wrong, but I didn’t see it like that and I don’t consider like that. Why should they wait?”

While Cancellara kept his lead, the lead changed hands in two of the other main competitions. Sylvain Chavanel of Cofidis, who was in the four-man breakaway, was first over seven of the eight climbs on the stage and moved into first place in the king of the mountains competition.

Erik Zabel, a sprinter with Milram, took over the lead in the sprinters’ competition by being one of the few able to stay with the main group over the final two climbs. Zabel finished the stage in fifth place, vaulting him past Tom Boonen in the race for the green jersey, which Zabel has won six times before, the last time in 2001.