Is it a confluence of coincidences regarding fallible human memory?
These people all had overlapping memories of seeing notices in Warsaw that American/British Jews would be deported, then knowing they were put in prison and talking to them, then seeing/knowing them being deported to Treblinka, then talking to them in broken Polish as they confirmed they were English-speaking Americans/Brits, then knowing they were murdered, then seeing their American/British passports/diplomas/currency/clothing?
It's very common for a group of anti-German Jewish-Soviet partisans to have overlapping, highly-specific memories of German atrocities that didn't happen at all?
But by sheer coincidence, the false memories overlap enough for the Soviets to construct a coherent narrative and draft an official report?
Alternatively...
- Did these Jewish partisans perpetuate a fraud on the Soviets, and the Soviets were "easily duped"?
- Did the Jewish partisans collaborate with the Soviets to perpetuate a fraud?
- [Insert better theory]