Sometimes you're out, having fun, doing what you do, hooning a car around a gravel road right next to a lake. And then sometimes you hoon that car straight into the lake, even though that's not what you're supposed to do, but because hey things happen.
It's actually not clear if this was intentional (although a bit stupid) a la the Texas Bugatti, as the guy holding the camera hops out immediately once the Peugeot hits the water and then starts cracking up.
Then again, he does shout "not in the lake!" in the beginning, and then seems to lament his situation, asking the car gods that have forsaken him "why? why? why?"
Because your friend can't control a FWD Peugeot on a gravel road, that's why.
H/T to _Mécanicien!