I saw that sort of construction on smaller, "back yard" type windmills, but all the large commercial blades I saw were 100% fiberglass. Of course, that doesn't mean that everything out there is all fiberglass. I built a composite airplane a few years ago and I've been into gliders for over 20 years, so I was curious about the construction since the blade is essentially a wing, just like a glider. I would be curious to see if the generator produces a large enough magnetic field when in operation and maybe that is what is causing the distortion?
Nearly every one of the 80’ class and larger have carbon fiber leading edges and tips.
Static charge generation is a huge problem, along with ice buildup.
The magnetic field would need to be oscillating near the frequency of the radar beam. You can spin a beam of electrons around that fast — this is how radar transmitters do it. A generator armature would send flying pieces into orbit before it got anywhere near that speed.