Hear the dialogs, made of wood
So I finally saw this film again- I've probably seen it as a child, long ago, but pretty much forgotten about it. And the first thing that stands out is the uninspired, stiff, wooden dialogs. Not a single pun or diversion, no irony or sarcasm, no emotion. Only an exchange of messages.
I was really wondering why the conversation was so monotonous when I checked the cast and, surprise, found out that many of the players are native Germans or Austrians (and the rest had to fake the German accent). Now my best guess is, that these Germans in 1974 didn't speak English terribly well- not good enough to express the finer intricacies of the language- so either their dialog had to be kept to a minimum, or they had to be lipsynced (yuck! But it would have been a just punishment for these jerries who've been synchronizing English films from the dawn of Fernsehen).
And then there's the old-fashioned cliché that German officers all barked commands all of the time, which is annoying, but up until the mid-eighties or so virtually all war films with Germans in them kept this up.
So I'm not certain that the dialogs were as flat as a pet halibut because of the actors, but they could have been quite a bit more interesting, more lively, if the director had maintained a more sophisticated level of communicating. It's still a fine thriller, of course.