The context of the following conversation is The rebels had burned down a village and murdered, so Addison executed every last one of them.:
Addison says I normally don't like corporal punishment, but the rebels had to be executed..
The friend responds What did they do to deserve such a thing?.
Addison responds They burned down the whole village. Not only that, but they murdered the survivors..
The friend responds That's an unforgivable crime..