So apparently (I wouldn't know this as the Tour De France has never really secured my attention as a sporting event), this happens quite often. As cyclists made their way from Annecy up to the Chamonix Valley overnight, a man by the name of Alexis Bosson, travelling in a perpendicular direction down the hillside, sent it over the riders on live television before landing on a run-out further down the other side of the road.
You can see in the video he even does a behind the back no hander, making it the most exciting 3 seconds of the entire race. Here are the antics from another angle.
That regular occurrence that I spoke of? Well in 2013 a similar attempt was professionally filmed and documented in the lead up to the stunt, which you can see below.
Dave Watson was another hero to make the leap back in 2002 at the Col du Galibier. His landing, however, wasn't ideal, making his getaway from authorities quite the effort after such a crash.