I think for this test to be accurate - the two formats need to be color corrected in the same codec and on the same system. Is the davinci making the colour correction off of the scan? If so- the available bandwidth is much greater than pro res 4:2:2 in Color. I think Red cine would provide more latitude from the footage than pro res and Color.
There is however, very little doubt in my mind that more highlights can be recovered from film.