Jim Prideaux goes off on his abortive mission to Czechoslovakia at the end of March. Following this scene is a strap-line that says "six months later". That should put the continuing action at the end of September. However, there is snow on the roads, and Roddy Martindale says to George Smiley in the restaurant "... I do hope you're not going to tip him. It's a guinea at Christmas".
When Prideaux meets his ride on the buildingless street in Czechoslovakia the car does a U-turn and then turns left. The car's offside tail light isn't working; when they arrive at the rendezvous it's working again.
In the distant shot of Jim Prideaux pulling away from a border crossing, adjacent to the Mobil petrol station and later when we see him driving away from the rear, he is driving a Mercedes Benz W114/115 (vertical headlamp cluster and short, 'fatter' tail lamps) however, the closer shots taken at the Czech border and thereafter are of a 'newer' Mercedes Benz W123.
When Control is briefing Prideaux he says, "All I want from you, Jim, is one word. Just the one codename." Two individuals-Toby Esterhase (Poor Man) and George Smiley (Beggar Man)-have codenames of two words. (Perhaps Control caught this when he says, "Just the one codename.")
Shadows of the crew on the pair as they walk over the golf course.