[PotatoHeadMick]

I don’t get it, how did the Mayor “betray” Private Digby? As I read it the mayor went to the soldier’s hiding place and explained that the Germans would execute everyone in the town if he didn’t surrender, the soldier thought about it overnight and decided to give himself up to the Germans.

I don’t understand how this can be described as the Mayor “betraying” the soldier.

[nickcarraway]

That wasn't the betrayal they were referring to. At that point, the English soldiers were already discovered.

What is being called betrayal is who turned the four soldiers in to the Germans in the first place.