As this discussion was developing, I was beginning to suspect it could also be a case of both, Rick
Internal reflections can be very crafty. They can be difficult to control, originate in the most unlikely of places, and the $$$ of the gear is no guarantee either.
As for the over exposure, this is something that has to be learned to understand consequences, be able to identify these aberrations when they show up & come up with solutions to mitigate them. AND the multitude of variations thrown up by using different gear.
Great thread, Kuz!
Alex.