[phba]

Well, it's impossible to know if Eichmann really thought about the ethics of his job. With regards to his trial, it didn't matter anyway. Every captured Nazi official claimed they were just a cog in the machine and had to follow orders. The judges rightfully dismissed this, because otherwise Hitler would have been the only one responsible (how convenient!). They were all put on trial for their specific actions and decisions.

My take from Hannah Arendt's work is that normal people will do evil things if they think they can get away with it.