Visible crew/equipment: When the man is hit in the face with a pie whilst having his picture taken, you can see a crew man's hand throw the pie directly in his face.
The Battle of the Century (1927)
1 visible crew/equipment mistake - chronological order
Directed by: Clyde Bruckman
Starring: Oliver Hardy, Stan Laurel, Jack Adams, Wilson Benge
Continuity mistake: When Charlie Hall slips on the banana skin with his tray of pies outside the pie shop, he places the tray on top of his left leg, but in the next shot the tray is under his leg.