Maybe I miss the point, but AFAIR the "danger" of the down-wind turn materializes only when the pilot tries to maintain a certain track
over ground during the turn, with the tailwind first making him faster (relative to the ground) and becoming a crosswind pushing him "outwards" (again, relative to the ground), which might tempt him to overbank and stall the airplane (and/or trying to compensate with rudder only and crossing his controls to avoid an "excessive" bank angle).
So
AFAIK the danger of the down-wind turn does not lie in the turn itself (with airplane unaware of wind direction), but in the reaction it might provoke.