A mention of Checkov actor, Walter Koenig, is appropriate here.
And also of House Minority Leader John Boehner. Or Wayne Newton's song Danke Shoen.
It seems to be American English standard for German names that have an o-umlaut or oe (which is the same thing; the umlaut started out as a small e laying on it's side on top of another vowel) to pronounce it like "ay", instead of like the German sound English lacks or even "ur", which is more like how I think most English speakers hear o-umlaut.
p.s. Curse /. and their lack of support for non-ascii characters.