Today Nikon issued an official statement on the Nikon D750 reflection/flare issue I reported over a month ago:
We have received indications from some users that when photographing scenes in which a bright light source, such as the sun or high-intensity lighting, is at a certain position along the top border of the frame, flare with an unnatural shape may sometimes occur in images captured with the D750 digital SLR camera.
We are currently looking into measures to address this issue. Further details will be announced as soon as they are determined.
Here is some additional information I received in the last few days:
