The Apollo command module environment was 5 psi pure oxygen. This gave the astronauts lungs the same partial pressure of oxygen that earth atmosphere provides.

The Apollo command module environment was 5 psi pure oxygen. This gave the astronauts lungs the same partial pressure of oxygen that earth atmosphere provides. So not even 14 psi difference, but 5 psi. A difference that can be dealt with during a repair. A commercial aircraft cabin while flying at 40,000 ft has about 8 psi of pressure differential