Hmm, are you sure these games are double checked? If so, when does the second check occur? I remember Dino Crisis on PlayStation going back for a second check after the game boots and Capcom logo is displayed [if the check failed, you would get a message informing you that something went wrong. It was easy to bypass though, by doing a second swap. Modchip owners wouldn't even notice it].
Saturn games lacked any kind of proper protection except for the ring. While PlayStation had its libcrypt [easily cracked for those who know what they're doing, but you could no longer do a 1:1 copy on the protected games], Saturn had nothing of this kind. There are a few titles which refuse to boot fully if you have any kind of cartridge inserted [Panzer Dragoon Saga for once. Boots with memory cart, won't boot with additional RAM / Action Replay / GameShark].