it was probably taking into consideration how those apple apps are "free" for new buyer, so its incorporating them into the free section too just for ranking.
This normally happens with app I the week. It gets thrown into the top 10 during the free period then the price gets reapplied and for a few days it stays top 10 in the free section.
As for the apple apps that's purely because the apps are free with new iOS device activations.