overpitched
I reckon forget about inertial reference frames and windshear and its effect and if a 60 KT headwind suddenly turns into a 60 KT tailwind. Any windshear has unpredictable efffects anyway and it sounds as if you are pretty confused by people taking everything to the n'th degree. Stick to the basics mate.
If you turn downwind maintain a safe AIRSPEED (unless you have HOGE power available). EXPECT the ground speed to increase.
Don't use the GROUNDSPEED as your judge of AIRSPEED.
Scan/maintain the attitude that gives you the airspeed you need, set the power you need to hold height, and keep checking the ASI.
The goal here is to not spud in if you turn downwind isn't it? Keep your AIRSPEED on and you won't. Simple.
How about you think it all out and hand us down the guru stuff?