Probably not vortex ring state
The likely scenario is that he was at slightly too high a density altitude to hover out of ground effect and let the rotor rpm droop excessively while trying to. (One clue is what appears to be a lot of coning of the main rotor on the way down.) Drooping the main rotor rpm causes the tail rotor to slow, which means less directional control thrust, to the point where he can't keep from turning to the right. Fortunately, he manages not to hit the main rotor or tail rotor when he goes into the water (that would be game over ). Once he's in the water, he doesn't need as much lift from the rotor and can regain rpm and directional control. He's also now in "ground effect", which means he has a bit more lift than he did at his initial hover altitude. That allows him to get out of the water and move forward to get into translational lift, which lets him fly away. Vortex ring state is a different condition and does not result in the loss of directional control seen here.