Joblow….I’ll take your example one step further. Time of useful consciousness at 41,000 feet in an explosive decompression is less than 10 seconds and requires pressure breathing oxygen. In your example, the brand new second officer and young cabin attendant in the cockpit fail to extract and get their masks on in less than 10 seconds….
The relief crew outside the cockpit will not have pressure breathing oxygen available to them as they attempt to use emergency door entry procedures to bypass the locked cockpit door and they succumb to hypoxia. The aircraft continues to fly until it runs out of fuel….
i raised this very scenario many times to Flight Ops management to no avail…..because…safety was their top priority.