not any kind of historical authority on my part but possibly due to the willingness you report ; he might be also ready to talk about people the West would find useful in the coming struggle against Communism .
He was from East Prussia originally, but I think he had settled in West Germany. It seems doubtful; the West was going through quite an orgy of prosecutions at the time, and most of the 'useful' Nazis, such as the Gestapo, had already been tried.
I don't think a trial would have been useful if the goal was just to keep him quiet.
If his suicide was really a murder, that might make a lot of sense. I don't think it was though; I think Blaskowitz was convinced that Goering had been right about "victor's justice," and expected to face a show-trial and a swift execution. He had some familiarity with such trials, having been under suspicion of involvement in the July 20 Plot (he wasn't) and having personally threatened Seyss-Inquart with one to force the latter's co-operation. Two of his fellow twelve generals on trial at the same time were acquitted, includng Hugo Sperrle, who most definitely committed war crimes, so he was wrong about that.
How much did they know about what he did do that was favorable towards him?
They didn't have all the information on Blaskowitz that we now have. We know now that he was probably the single most respectable and honourable general the Germans had, and his military skills are finally gaining recognition. Nobody could execute a retreat like Blaskowitz, which is likely the most under-rated quality a general can have. But the prosecutors certainly had enough information to see that he didn't commit war crimes.
His official complaints about SS actions in Poland were on record. I don't know if they were aware of his attempts to execute SS war criminals on his own authority. Probably not, given the SS's obsession with destroying evidence of their war crimes towards the end. His objections over atrocities in Poland survived because they were in Hitler's personal files; he hated Blaskowitz, and only retained him out of a grudging respect for his abilites.
Blaskowitz's actions in Southern France weren't well-known, but he basically commandeered the Netherlands from Seyss-Inquart in March 1945, and the Dutch resistance had reported on his willingness to look the other way when they launched food raids. He was also on record as negotiating to allow food drops to the Netherlands during the latter stages of the war. Seyss-Inquart wanted him to destroy the dykes and flood the Netherlands, but Blaskowitz conveniently lost contact with his entire corps of engineers - despite sleeping across the street from them - just long enough for the Flensburg government to order his surrender.
He was on good terms with the Canadians who he surrendered the Netherlands to, but I don't think the Americans liked him, even though he gave them most of Southern France without a fight; Blaskowitz was likely the best general in the world at the time when it came to successful retreats, and he basically extricated the entire German Army in Southern France from under the noses of the Americans. He also evaded larger French, British, and American forces in his successful retreat from Alsace-Lorraine to the Netherlands (not exactly an easy trip, and he technically took his troops behind the American front to evade Patton at one point, earning the latter's undying respect), and he only got stuck there because the Canadians stopped trying to chase him when he entered their zone. According to his adjutant, he'd already worked out a way to flee to Denmark if necessary, though even his talent for retreats would have ended there, with his back to the sea.
Sour grapes from the Big Three Western Allies about all that could have played a part, though it seems a little too petty. Maybe if FDR were still in charge. It just seems like there was no reason to try him. Other generals who were acquitted may have at least had a case to answer for, and needed to defend their actions - Sperrle cleverly brought up Dresden at his trial for the Blitz, causing the British to try to shut his trial down - but Blaskowitz was never even
suspected of war crimes. Not even of helping plan the invasion of Poland; he was the military governor of Bohemia and Moravia at the time, and didn't show up in Poland until after the initial invasion.
