Good to see Zuse on HN. It's possible to go and see his machines in Germany and I highly recommend it. This is a "forgotten" part of computing history because of WWII and deserves the light of day.
I can highly recommend a visit there. Not only you can see an original Z4 and a replica of the Z3, but also lot's of more science and history related exhibitions. Don't miss the Enigma!
Z22 is at ZKM in Karlsruhe, but Deutsches Museum has a whole department on Z3 and related machines. I can highly recommend it to anyone interested in (very) early computers!
The article makes it sound like he waterboarded him, but that's probably just because the word 'interrogate' has become so unpredictably uncivilized in recent usage.
It seems like there was probably a degree of duress and that this was a continuation of a series of "interrogations" where perhaps a greater deal of duress was necessary? Not that the German scientists were necessarily unwilling but that they were anyway required to attend:
>"As the behaviour towards German scientists had already improved considerably in 1947,the interrogation had the more elegant form of a small colloquium. A handful of German specialists from Göttingen had been invited among them also myself. The significant German people who there gave talks were Professor Alwin Walther who had been thoroughly concerned with Hollerith machines and differential analyzers at the Darmstadt Institute of Technology, and Konrad Zuse with his relay calculators. If in addition Professor Friedrich Willers from Dresden had also participated, all leading German scientists who have been busy during the war in the development of sequence controlled calculating machines would have been there. Though Willers was in the Soviet occupation zone and therefore probably not available for the Britons." (http://www.mathcomp.leeds.ac.uk/turing2012/Images/Turing_Zus...) //
Note that Porter from the NPL later mentions performing an "investigation" as part of a military operation, in his military uniform (despite there being no requirement to do so). Also:
>"Undoubtedly, the participation at the colloquium of Göttingen was not optional. (ibid, p.5)"
tl;dr - It sounds like there's evidence to suggest Turing had an unreported meeting with Zuse in 1948. There is also a suspicion that Turing could have met with Zuse in 1934 on a trip to Gottingen.
The bit about wearing a military uniform seems strange.
My grandfather was part of a similar investigation of the German electronics industry, he had done his PhD at Aachen in the early 30s and found that he already knew all the senior people, I can't imagine him wearing a uniform.
One funny detail I read about those machines is that he had to steal (due to war shortages) copper cables from public telephone lines, which could have lead to death penalty (because of sabotage).
http://www.deutsches-museum.de/en/exhibitions/communication/...
Here's the Z3 in action (German only, try subtitles):
https://www.youtube.com/watch?v=aUXnhVrT4CI