When Gonzorgo and Roderigo are trying to hide from Barnaby after he discovers they sold Tom to the gypsies, he throws both of them over a hedge and on the ground. When they fall on the grass, it's obvious that it's artificial turf, because it moves with them.
When Barnaby, in his opening scene, closes the window shutters on Gonzorgo's and Roderigo's hands, the window sill bends as if made of foam instead of wood, so that the actors' hands wouldn't be injured.
At the end of "Go to Sleep" while Mary is singing, the shadow of the camera is over her right shoulder.