Forget the wind speed. Whether calm or 20mph. Think stall speed.
If you slow your plane down to its stall speed it stands a good chance of stalling. Whether it is flying in the calm or in a gale.
As has been said in many posts, don't throttle back too much on the downwind flight. Don't relate your planes flying speed to ground speed.
Turbulence, wind shear, gusting etc, can happen at any time. Down wind, across wind, and into wind. Don't confuse those with slowing the plane down yourself to near its stall speed and then turning. Turning creates more drag, more drag reduces speed. Crunch!.
Looks like we are running out of excuses for crashing other than blaming ourselves
But then there is always, "Did you see the air shimmer just before the she went down ?. Darn it!, ....I reckon there's a cloaked Klingon Warbird over the field. ....shot my plane down."