Hi Mark,
I am sorry to say and I didn't have anything to do with your rejection (obviously as I am not a headscreener), but I fully agree that the sun angle is poor and due to the very high sun the underside will always look underexposed so that goes in-line for me. Overall the shot has a dark feeling, so I agree with both rejections the second just explains the first.
I would personally not recommend to take other shots as a reason why any shot should be accepted. Generally without referring to your shots at all, but other wrongs don't make anything right. Such a sun-angle is always borderline, so surely some "similar-lit" shots might make it as well.
Here is the shot, for the interested:
https://imgproc.airliners.net/photos/ai ... cd7fe3777fJulien