When the man is harassing the first lady, she pulls her skirt over her knees, but in the next shot the knees are not covered.
When talking to Jefferson in prison, the senator's blue right shirt collar goes in and outside of his suit coat.
When Janice leaves the station, there is no Underground sign, just a national rail sign. She was traveling on an underground train.
When Grieff explains the mysterious payments at the end of the episode, the note he passes to Kempton shows "$253,55 cents" -- using American currency conventions, the message should read "$253.55".