@Winnie: A few years ago, the FAA finally caved in. In the new Helicopter Pilot Handbook published by the FAA, it is called VRS.
For this case here, one might consider the following. In a flare, you do not use a lot of power, if you come in really hot, the collective might even be on the floor. Otherwise you balloon up up and away and with it your NR. The rotor is therefore in a windmill state. In this state you can not have VRS. As you can not have VRS in an autorotation. VRS can only develop, when you bring in power and since the vortices need time to build up, it will not be immediately in the VRS state. But the surprise was, that the flare did not bring the intended result, i.e. stop the forward speed and the descend rate, the floor came up faster than the pilot could bring in the power and develop any meaningful VRS. The PROBABLE cause of the accident was NOT VRS. The probable cause was a tailwind approach with way too much wind where the pilot did not anticipate the higher than normal sink rate. This kind of accident happened many times over the years. One is even documented on film by Robinson. During certification testing, the FAA pilot flared aggressively, levelled the ship and hit the ground. The blades folded down and chopped of the tail. The FAA pilot jumped out an threw his helmet on the ground. He wasn't a happy camper. And that was into the wind. I asked some more knowledgeable pilots if that could have been caused be VRS and the answer was no. It was HTG (Hit The Ground).