When a movie is expected to achieve global success, it's dubbed into various different languages to ensure it remains accessible no matter where it's seen in the world. That means there are versions of 'Saving Private Ryan' dubbed into almost any language you can imagine.
One of those languages is German, and those responsible for the German language version decided to go with authenticity as their watchword. For one of the more prominent German soldier parts in the film, they contacted a real German World War II veteran. He initially agreed to the part, but when he started work he unfortunately found the whole process too traumatic and had to pull out because it was upsetting him. That's a shame, but it speaks volumes for how realistic the film must be if a survivor of the real war considers it to be too close to the bone for him to come anywhere near it.