When Sonny is at the Irish pub, he walks to the right, away from the bar; the shadow of the camera can be seen following him upon the back of the bartender, two patrons at the bar and so forth.
When Sonny is in disguise at the barges, the shadow of the boom microphone can be seen in some shots.
Terry Thomas' character blinks twice as Joan Sims backs into him in spite of him being unconscious.