Aesir,
The S-76 has a rotor brake which allows the pilot to start the engines and then engage the rotor. If there is significant tail wind, the brake should not be used, as engine exhaust can be turned upward by that wind and impinge on the blades, perhaps causing local hot spots that could bubble. The operating instructions explain all this.
If that had happened, replacing the blades (which would show obvious overheat damage on the lower surface) would eliminate this as pertinent information relative to the accident.