Yes it contradicts, the yellow of your friend has no colors as an sub-adult, but a strong reduction of pattern.It's closer to a green with a yellow head.Is it genetic ?
My babies don't have a pattern reduction but are colorfull and will devellope colors with nearly no black, their eyes are orange and have a proved genetic transmition.
I understand your point, but you can't compare the genetic of boa constrictors. Very few of the pastels boa are genetic, they are polygenic with very different phenotypes with or without much colors and not much possibilities to predict the breeding results.Not all the hypo boas have a stong pattern reduction. With those the result is a litter with the same phenotype on all the babies.
That's why I call them hypo unless I find an other term more approriated but I haven't untill today.
Thanks for your comments.