He served the prosecution by suggesting that Himmler at Wewelsburg demanded (rather than merely prophesied) the deaths of millions of Slavs and Jews
He can suggest all he likes, in fact he could have declared that Himmler ordered the Jews to be sent to the Core of the Sun by the Himmelsfahrt Sonder-Raumschiff Dienst blasting off round the clock, but without corroborating evidence it's just not evidence.
According to Browning, Zelewski gave the Bundesarchiv two of his diary books. The second was in the original version. The first volume was not, but was retyped, and according to Browning the Bundesarchiv “said we cannot certify this as a copy of the original because they didn't get the original so they alert the reader to the fact that it is not the original diary book of the man, so you can indeed be alerted to the fact that it...possibly had been changed."
Which brings me to another point, the chain of evidence, which seems to be almost universally lacking & ignored for those supporting the Holocaust Narrative.
Brownings Statements, Opinions, Observations & Speculations can not be considered as evidence for anything, Brownings Statement about a "retyped" Diary could have should have been backed up by either the testimony of a representative a letter or an Affidavit from the Bundesarchiv, all of which would have been easy to obtain, yet we have nothing except his word
However if all true, we can also speculate that the Diary was retyped by Bach-Zelewski because that section of the Diary contained Personal entries which he simply did not want anyone else to see, such as a liaison with a mistress or similar, it did not/does not have to pertain to the Holocaust, after all, it is a Diary, not an official Army Document, it was personal & in fact he didn't even need to lodge a copy with the Bundesarchiv but he did so anyway of his own free will which is obvious otherwise the original Diary would have been forcibly lodge by the authorities.
And as you yourself have noted :
Even without having seen it I am confident that B-Z’s diary, whether copy or original, contains nothing to support claims of a genocidal massacre at Minsk or elsewhere; otherwise it would been entered as an exhibit
Back to the chain of evidence & why it is so important.
Nathan, as you noted :
in the written answers submitted (from abroad) to the Eichmann trial in May 1961
But what isn't made clear to the layperson reading this material is the fact that when/whilst Bach-Zelewski was submitting this testimony, there would have been not less than 5 other people present (that's a conservative estimate)
1. A Justice of the Peace, Justice, Judge or similar empowered Judicial Officer
2. Bach-Zelewski's own Legal Representative, to ensure he wasn't implicating himself & that he was immune from future prosecution.
3. A Representative from the Defendant (Eichmann)
4. A Representative for the Prosecution
5. An Impartial Witness
Understand also that at this very point, the Prosecution through their Representative have the right to view any evidence/material & may examine, cross examine or dispute the Witness or Material being presented & may even submit for the Witness & Evidence to be found inadmissible through the Presiding Judicial Officer, Further to that, if the Witness & sighted Evidence is accepted, the Prosecution can still have the Witness & Evidence struck at the Eichmann trial if the Presiding Judge for that Trial deems that an appropriate course of action.
If Bach-Zelewski is a Liar using a Sanitized & White Washed Diary you have to ask yourself why it was still submitted as evidence & who benefited?
It really is a mute point anyway, the Eichmann Trial like all the other Holocaust Trials was a foregone conclusion, they got the only outcome that was ever going to be possible from these show trials no matter what the Eyewitness & Evidence stated.
Again as you have said :
the question remains: when did a firing squad of partisans become a massacre of innocents? It cannot be honestly sourced to BZ. One villain of the piece may be Professor Richard Evans, who footnotes this claim to Himmler’s desk diary of 15 August. I suspect it will lead back merely to one of Himmler’s commentators.
It seems simple enough to me, Himmler's Diary as I understand it more or less shows an Itinerary, so we can surmise Himmler's entry for August 15 was :
August 15, bound for Minsk for inspection of ongoing Anti-Partisan Operations.
He arrives, has a tour, Confers with Wolff etc, inspects the Einsatzgruppe, rests, whatever, by the 17th he witnesses a Legal Field Courts Martial & witnesses the execution of up to 30 Partisans.
then some Post War scholar (Evans) comes along & the entire story changes, the rest is history as made by the Holohoax industry.