FH1100, I think you have it just about right. The academics of the two are almost meaningless in the operators' world.
I'm tending towards SWP being the end result of a VRS when that VRS is not corrected and the aircraft is generating enough lift to sustain the VRS and does not drop through into autorotation. It matters not. They sound the same to me.
I did get it at 4000' in the hover at night but recovery at the first sign of trouble was instinctive and very easy to fly out of.