Yesterday over SE Colorado, staying down at 10-12k ft, I was staying low for wind, but planned a climb for terrain after AKO, enroute to COE. My pneumatic door seal blew out, and the cabin depressurized in about 3 seconds, just as if you had hit the switch to dump the door seal.   I will guess that the pros put dual seals in to prevent this. It might have been a serious issue after a climb  into the flight levels for several reasons. Usual suspects are:, hypoxia, ear pop induced Coriolis effect, spatial disorientation, very cold breeze, etc.   Anybody ever look at redundancy here. Maybe a dual seal? R/ Bill Miller PS If there's interest I will tell about attempts to patch the pinhole on the inboard wall of the seal, while limping to destination. Any guidance there?