... but the seals have all been broken by now, right? So maybe the re-caging Sam (and Dean) managed at the end of S5 wasn't at the same security level. (Also, Sam and Lucifer aren't in the *actual* cage, right? more like some kind of holding cell from which Lucifer might still have trouble travelling topside.)

I'm reaching a little but I don't think it's necessarily the enormous stuff-up it might seem.