Plenty of Nazi scientists and war criminals were given amnesty in the US after the war in exchange for their knowledge.
Let me remind you that ALL the Allies war criminals were also basically given amnesty everywhere, just because they were victors.
if you think that's fair, well that's your call.
And the ongoing killing of prisoners who surrendered (a US army speciality in the Pacific, no prisoners, just kill them all)
I don't think it was right.