Visible crew/equipment: Towards the the end, when Scrooge wakes up in his bedroom on Christmas day and is elated to know he is still alive, he goes over and looks in the mirror twice. Both times you can see someone in the mirror reflection in the background, possibly holding a script.
Continuity mistake: During the scene where the younger Scrooge and Marley are addressing their business associates, Marley's hands keep changing their position between shots. When the scene shows the entire group, his hands are on either side of his lap with his thumbs hooked in his vest pockets. During the close-ups of him and Scrooge, his hands are clasped together on his lap.