When Col. Alex Vorda (Anthony Zerbe and Erhard Poltzin (Tony Van Bridge open the crate containing the isotope, Poltzin has a large spot of dust on the left shoulder of his jacket. There is a quick closeup of Vorda and, when they cut back to Poltzin, the dust is gone.
The date on the cigarette lighter is in the format month-day-year which is only used in the US.
When the container holding the isotope is lowered into the truck, the container bounced suggesting it was a large rubber ball.
When Jim is listening to the tape, the recorder is running in reverse. It's rewinding and a very close look at the switch proves it.
When Vorda goes through the gate to the warehouse, there are palm trees to the upper right. There are no palm trees in Europe.