One problem-- the limit switches on the outflow valves will limit the cabin to about 14,000' by going fully closed, then the leak rate of the plane and whether the packs are turned off will determine the ultimate cabin altitude. Yes, it would eventually reach the plane's altitude, but it would take long enough that a "cabin riot" could be mounted.
One pilot taking out the other with a crash axe is more likely. Turn off both packs at F450 in a Global and the cabin only rises at about 1,000 fpm. The outflow valves almost immediately go closed trying to maintain the cabin altitude.
GF