That's too bad, FT. I can see how this could happen if a skinner's PC has the Environment setting set to off. They would never know anything is off - the skin would alway look Ok to them. I stopped skinning before these bump and spec map files came into use, so I don't understand how to use them or check for problems. Seems to me this kind of thing would only reveal itself on a different PC than the skinner has. Perhaps skins need to be looked at on several different configurations?
I have seen this effect on some P-51 skins too. It makes them look like Nevada air racers, not warplanes.