"The Bible Students weren't part of the Watchtower Society at the outbreak of WW2"
I think you here have a very USA-based view on the matter and try to make that view true also for Germany, but that is utterly false. The name JW did not "hit" in Germany, and they were known as Bible Students - Bibelforscher - all the way down to and thru WWII. True, there were a very few BS in the US sense of the word also imprisoned, but in Germany JWs were known as BS and hence were very much part of the WT.
As to what the female prisoners are told to have said - I think it so very easy for us living under more or less peaceful conditions to think that "now that was strange!" when we see how people reacted in the camps, what survival strategies they chose etc., but it is so totally impossible for us to imagine what it would be like to live under such conditions. I think it is more than probable that quite a few us would have signed any paper at all or given names away freely only to get 5 minutes more, when the guys with guns and sticks and dogs gave us the best of what they had been taught to give ........ Austrian JWs suffered the highest amount of victims - deaths - as they were most "fanatical" of the JWs and refused to greet guards, to work etc., whereas the German JWs found strategies they could defend as to work, food, greetings etc., they gave a little, bended it a little, so that they could survive - survive to tell and to continue their work.
And who are we to judge people who suffered so extremely that it is impossible for us to comprehend?