By moving the finish line 6 km down Mont Ventoux on yesterday’s stage 12 of the Tour de France, race director Christian Prudhomme hoped to avoid the havoc that wind gusts at the top might cause but in the end mother nature prevailed and was responsible – albeit circuitously – for one of the biggest polemics of the race ever.

Down in the trees below the new finish line at Chalet Reynard, the wind was still powerful enough to thwart any attempts at erecting barriers in the closing kilometres as is normal procedure.

As the stage was nearing its conclusion, a TV motorbike was brought to a stop among throngs of spectators with 1.2 km remaining, and BMC’s Richie Porte, Sky’s Chris Froome and Trek-Segafredo’s Bauke Mollema all ploughed straight into the vehicle.

While Mollema managed to get up and away almost instantly, yellow jersey Froome was forced to carry on frantically on foot, and it looked as if the Tour were heading for one of the most controversial episodes of recent times until the decision was made to take GC times at the point of the crash.

"The decision yesterday to move the finish line was indispensable but as a result there was congestion at the end of the stage," race director Prudhomme told reporters looking for answers in the middle of the bedlam half-way up the mountain.

"We weren't able to erect the barriers in the final kilometres because they just blew away," added Prudhomme.

Furthermore, the race director explained that the decision was not taken by himself or ASO but rather by a commissaire panel from the UCI, the sport's governing body. He also said there will be an inquiry to determine precisely how the accident unfolded.

Prudhomme labelled what happened "an exceptional situation – unprecedented even", the like of which he has never come across over the course of his career – "neither as a journalist nor as a race organiser".

During the aftermath of the chaotic stage, Richie Porte aired his frustration at the minority of roadside fans who failed to respect the race and the riders through their thoughtless and idiotic behaviour and Prudhomme did recognise the behaviour of fans as a big problem in the context of the incident although he was more careful in his wording than Porte.

"There was a considerable influx of spectators with some great people of but also some who were more excitable," he said. "And with all those people it was impossible for the TV motorbike to pass through. I have to repeat it every day, and I rely on you [the media], too, to spread the message, to urge people to be more attentive."