Factual error: When the exchange is made in Berlin it is bitter winter with snow on the ground. But Donovan returns to New York (the TV newsmen is reporting that Powers has been returned "earlier this morning") so it is within hours, and yet the leaves on the trees in NY are green, the grass is green, people are in shirtsleeves. Berlin and NY share the same seasons.
Suggested correction: When Donovan returns home, outside his house the trees are losing their leaves. There are lots of leaves on the ground and one tree is leafless. Apart from Donovan and his wife, the only people outside in this scene are two people walking in the background, who both have coats on. In a later scene, people on the train are all wearing coats. Donovan looks out of the train window, seeing snow on the ground and people wearing coats and hats. No one is in shirtsleeves.
Other mistake: In several scenes in Tom Hanks' home the TV has a set of rabbit ear antennae, but to the right of it is an antenna rotatory control for an outside antenna, I would think in Brooklyn rabbit ears are all that was needed.
Suggested correction: Having something that's possibly not needed doesn't make it a mistake. Maybe they have an external antenna that they no longer need but keep the remote handy just in case. A bit like how some people keep old mobile phones, glasses, etc. they don't really need.
