Neff's Lousy Acting as Dietrichson
So, Neff knows that Dietrichson sounds different than he does. Yet, on the observation platform, he talks in his regular voice, not at all trying to sound like the man he's supposed to be imitating. And, he isn't acting like he's hurt in his voice. Wouldn't you rough your voice up to sound like Dietrichson, plus throw in some grunts and groans? How about hunching over a little? But, Neff doesn't do any of it. I've seen this LOTS of times, but this certainly stuck out to me this time.
Also, Neff's fingerprints are also over EVERYTHING, including the crutches and the handrail on the Observation Car.