Once the captain's body cools, the "get out of my seat crowd" will be all over this. Never-mind the facts: There was practically no compromise in safety as all F/O's hold a captain's FAA type rating in the aircraft they're flying and this F/O had to be under age 60 by FAR. The FAA backup system worked perfectly; as it should, the same the failure of an A/C pack, or a hydraulic pump: Redundancy works, it provides practically the same level of safety.
The captain's name was, Henry Skillern. RIP sir, and condolences to his family.
And yet even BEFORE the body cools FI's spokesman for one-set-of-rules-for-me-and-a-different-set-of rules-for everyone-else has to chime in.
You're worse than anyone you would assail as "get out of my seat" and you're just as bad as any pilot who crossed a picket line. You're weak.