crab,
The real question to ask is "How can a helicopter be descending at 3000 fpm and NOT be in windmill brake state?" By definition, VRS can only exist around about 0.7Vi to 1.2Vi (give or take). Here is a plot for a jet ranger, where the true VRS (the dark oval) is clearly between 1000 and 1600 fpm:
http://www.safetycenter.navy.mil/MED...n03/vortex.htm
For a low disk loading helo, the position of the collective in a vertical auto can easily be high enough to be in the powered flight range.