...On the other hand, what's wrong with an unbalanced fight? An U-boat being mercilessly hunted down by a destroyer is good material for drama even if, and perhaps especially if, everybody knows from the beginning that the U-boat is toast skagen with extra tragedy.
Absolutely, and in this case, it is very much like a classic submarine story of infiltration for intelligence purposes then try to escape and evade. Any number of things could have gone wrong for either side. I think it worked extremely well.