The Handler (Kate Walsh) mentions that Joseph Spah decided not to sabotage the fuel tank in the matter of the first case she gives to Five (Aiden Gallagher). Spah was a French-born, American acrobat who survived the crash of the Hindenburg by leaping from a window and tumbling away just before the craft hit the ground. He was accused of having planted a bomb on the Hindenburg, but cleared by the FBI due to lack of evidence. German authorities never believed Spah was innocent, however.

When Klaus' friend Dave got shot in the flashback scene at the Vietnam front line, the blood pattern covering Dave's face (mouth) changes multiple times while Klaus is asking for help.

References Miller's Crossing (1990)