I didn't know that
He told them one of Jews was his wife, and if they were going to shoot her, they could shoot him also.
So they did.
The book "Ordinary Men" is based on thousands of pages of transcripts from a war crimes investigation in Hamburg in the early '60s, where almost a whole reserve police unit made up mostly of mainly men from Hamburg who survived the war and went back to Hamburg were interviewed and the interviews cross-referenced.
The focus of the investigation was, naturally, what the Germans did, but what struck me when I read it was how often stories of Polish passive (or active) resistance kept cropping up. For example, they complained that the Polish police would disappear or call in sick when a ghetto was liquidated-- they had to threaten to deport the Poles as well sometimes to coerce assistance. Anti-Semites or not, they weren't murderers.
As a side note there were also always a few German soldiers who simply refused to kill innocents (a favored trick was to close their eyes and raise their rifles when everyone else fired). They were assigned KP duty afterwards, but were mainly not subject to any other penalty.