The way that I picture it is like a hollow doughnut or toroid which itself rotates in the same direction of the blades. This may be completely wrong, but it does make sense to me.
Joe, In which case I see your misunderstanding. But no, that's not what happens in a free air hover or in forward flight.
In response on another thread, "SeniorPilot" recently posted this link. It shows the downwash pattern very clearly. I think you will agree that anything caught in this type of airflow would not circulate around the helicopter in the manner reported in the Airprox, but be blown down and away.
205FuelHaul2004-40C.flv