Brandt accent
I assume it was intended to sound German. Did it? It seemed to me a bit odd, more Dutch than German...?
"I beseech ye in the bowels of Christ, think that ye may be mistaken."
It sounded a bit weird indeed , not specifically in a bad way . A very common thing in old War movies and series where German Officers are portrayed by British actors . It just sounds very classy and British with some occasional tries to sound German .
He speaks in the exact same fashion in Star Wars : The Empire Strikes Back , for what little time he is on screen .