Is it this area you're taking about?
If so, you could ask him to open that up a bit more. I traced the contour lines and the outer white one (bigger of the two) is where light will reflect off of and give the effect of being more open looking like in the inspiration ring.
It's hard to see in these "plastic" models without it being rendered in a metal surface. You could ask DK to do a render in metal and see if it still looks like it needs a change.