The Western Christian churches use Dec 25th, which was previously the date of the Roman festival Natalis Solis Invicti, but the Eastern Orthodox churches use Jan 6th. Additionally, most evidence points to the year of Jesus' birth as being 5bc.
Mercedes look like they were anticipating iasues before the race started - they have taken a barrister in to see the stewards and the appeal panel. Where did they find a barrister at short notice ?
If they had let all the back runners past so as to restore the status quo the race would have finished behind the SC. For whatever reason Race Control decided that the title should be decided by a straight shoot out between the drivers who were joint leaders in the championship going in to the race.
The SC came out with 6 laps to go. Unless they had deployed the virtual SC instead how are they supposed to maintain positions ? What if they had red flagged the race and then had a full restart from the grid for the last 5 laps ?
A safety car will always wipe out a lead. It has happened many times this season, as well as all the previous ones since SCs were introduced. Teams know they are likely, on which circuits they are more prevalent, and plan accordingly.
The stewards mucked up the decision on lap 1, and Race Control later decided that the championship should be decided by a racing lap rather than behind the safety car. RedBull gambled when the SC was deployed whilst Mercedes missed the trick.
There is no regulation that says lapped cars must be allowed to pass the SC.
EDIT: Toto Wolff complained to Race Control, who responded with "It's called a motor race".