Firstly, it is simply untrue, even in the Soviet show trials, that a dissenting voice was never heard. Vidal-Naquet cites the denial, made in court, by Krestinsky, which can be viewed here. Krestinsky had clearly been tortured enough for his persecutors to believe that he would confess in court, but on his first court appearance, he retracted whatever confession he had promised to give, and had to be subjected to further (presumably even more vicious) torture before he caved in the following day. Krestinsky thus proved, with great courage, that someone being tortured could still "have his day in court", even if his torturers defeated him subsequently. Furthermore, Vidal-Naquet notes that, when French deniers compared Hoess to Bukharin:
The comparison was unfortunate since Bukharin recognized practically nothing except his political defeat; those who were actually judged publicly, moreover, were only a minority. Certain others among them, such as Krestinsky or Kostov, retracted their confessions.This leads to the second point, namely how show trial confessions differ from those of Hoess and other SS officers:
Eichmann's lawyer in Jerusalem, Servatius, claimed as much: "Hoess's testimony is characterized by the fact of his total submission," but I doubt that any other reader of the autobiography would have that impression. Hoess proliferates autobiographical details, insignificant but authentic facts, personal comments, the most varied political commentaries (including a denunciation of the Soviet camps), anti-Semitic and anti-Gypsy accusations. Nothing in it suggests either fabrication or dictation. Upon being arrested by the Allies, Hoess was beaten (and why should we disbelieve him?) several times; he disavows his first signed statement (p. 244); he was also mistreated by his Polish guards at the beginning of his incarceration in Cracow (p. 247). At Nuremberg, on April 15, 1946, he was first called as a witness for the defense by Kaltenbrunner's lawyer, Kauffmann, a fact which Faurisson, normally so garrulous on the subject of Hoess, omits mentioning.SS perpetrator testimonies are replete with statements that do the prosecutors no favours, and which could indeed harm the prosecution (e.g. revelations of torture; condemnation of Soviet camps). Their political content is often antisemitic and contains statements defending Nazi actions. This is entirely different from the Soviet show trial confessional, in which the Stalinist regime was primarily interested in full self-condemnations that discredited all of Stalin's opponents.
To Vidal-Naquet's arguments, I would add a further comparison: McCarthyism. This anti-Communist crusade, also known as the Second Red Scare, used the investigatory and accusatory powers of the state, was close in time to the Nuremberg trials (which were still on-going when McCarthyism was beginning), and must thus have involved similar institutions and technologies of interrogation as those used by Americans in postwar Germany. McCarthyism was also just as aggressive in its intentions as the Nuremberg trials and de-Nazification. The [Jewish!] Judge in the Rosenberg case stated that:
I consider your crime worse than murderYet the prosecution could not elicit a confession from the Rosenbergs, even after coercing Julius by threatening to indict his wife. Moreover, this huge investment of state power did not involve a mass forgery of documentation. The Venona decrypts, which would have made convictions easier, were not used.
McCarthyism was therefore a political witch-hunt without a sophisticated hoax, and thus refutes the denier claim that the one must involve the other.