Continuity mistake: When the portraits of the various Santas are shown, when we see Malcolm's, it is at the end of a wall, with a left turn immediately afterwards. Later on, when Arthur and Steve are talking next to the same portraits, the wall does not end and continues down the corridor to a set of doors at the end.
Continuity mistake: Arthur's older brother gets "bombed" by a seagull. In the very next scene, there is nothing on his jacket, but the offending "message" appears again a little later on.
Continuity mistake: Arthur runs after Steve with the Santa game piece and bursts through the swinging doors which close behind him. Yet, the doors are open again when they are talking and Steve tells him to shut the doors.
