maybe another female in her viv which is in fact a male? and she produced eggs from two different pairings?
would be a possibility?! I know somenone, who produced hybrids from hybrid x guttatus pairing. after first clutch he bred guttatus male to same female and she produced a second clutch. mostly pure guttaus corns in the eggs - and two or three hybrids (I think getulus was involved, so seperating them was pretty easy). Something like that would explain your results.