Obviously the old gyro is more vulnerable under these conditons but turning downwind at low level in higher than usual winds certainly has it's risks. I can only compare it to ships losing helm ability in a following sea. It's all fluid ain't it.
I can't infer the gyrocopter's vulnerability from your story...
It is very possible that the pilot did the same thing that other pilots have done in the past -- used the ground as the frame of reference for his turn when there was a significant wind. If it was an open gyro with minimal or no instruments, the probability is even higher!
The "following sea" analogy is an interesting one, worthy of some further thought. As a sailor and kayaker as well as a pilot, I've fought following seas in many circumstances, but haven't quite been able to correlate them to flying yet. Maybe in a helo, when the gust factor is higher than the forward airspeed...