My brain is exploding.Apparently the way I chose to post above did not work. let me try again and see if I can correct the formatting....
TMI ALERT!! If you are interested, I am posting technical thoughts/opinions here, But this is where some of my kids would start rolling their eyes!!
Yes, that is an interesting issue I want to explore as well. From my current position, Scute placement happens before sex determination in the embryo development. Placodes form on the carapace of the embryo at about day 22 in a 90 day incubation - which sets scute placement. By day 31 the carapace scutes would be delineated. I am believing the start of the process that develops sex starts at day 25-28. At that time, the hormonal balance - in particular the production of aromatase, either will convert androgen to estrogen at higher temps, or, at lower temps, not enough conversion takes place - resulting in gonadal development. This is a cumulative effect. So the longer the yolk environment remains rich in aromatase - the more estrogen developed - female sex organ develops.
So - the earlier conditions around and up to day 22 through 30 would be effecting scute placement and delineation, while conditions starting at day 25 and probably lasting until about day 55-60 determine sex outcome. There is an overlap, so I would theorize higher temps at day 20 or so, could lead to abnormal scutes, and start the process leading to female. This would account for why most abnormal scute tortoises are female. But high temps with a subsequent drop in temperature around day 30-40 start limiting additional aromatase production and then results in a male. Since the temperature effects of sex setting are cumulative, higher than normal early temps that would possible cause scute deformity, would require a longer, cooler environment to reverse the starting of the female cycle. That would account for why male scute deformity is relatively more rare.
So that's my thoughts on this so far. I don't see it as a humidity issue at this point of understanding. BUT... So much yet to learn and discover!!