I don't see how this could be remotely accurate. I recently did a ride with a small group and one of us had a power meter in the pedals. We went North at 23 to 23.5 mph and even leading this pace was not too hard thanks to a nice tail wind. While toward the back of the line, this was pretty easy.

BUT we then turned around into the wind and we all worked a lot hard to maintain about 18 mph. Even though Strava said I was using less power going South into the wind, I assure you I was working a lot harder. The actual power meter on the other bike said he was generating more then twice the wattage then Strava said I was using. But on the Northbound tailwind part of the ride, Strava said I was at twice the power output then the actual power meter was.
Ok, sure, were talking about two different riders on two different road bikes, but we were in the same pace line so it should have been pretty close, a lot closer then +/- 100%