The US Army helicopter that collects Grant and Soviet livery that drops off Zaitzev in East Germany is appropriately painted, but is a Aérospatiale Gazelle of French manufacture and would not likely have been bought by major foreign military powers.
When the coach is traveling through the streets of West Berlin, the man sitting next to Jack Grant tells him the border crossing is just around the next corner. The coach is seen passing the Kaiser Wilhelm Memorial Church and then arriving at Checkpoint Charlie a few seconds later. Both landmarks are several miles apart and the church shown is deep inside West Berlin, nowhere near the East German border.