Visible crew/equipment: Two wires can be seen attached to Lavender (because light shines on them) as she floats back to the ground after the Trunchbull charged towards her. This is only visible on video, and has been taken out of the DVD, although you can (barely) see the shadow of the equipment letting her down on the wall behind her.
Visible crew/equipment: When The Trunchbull lifts her car back to her house and gets frightened by a black cat, a camera is reflected in her car on the left side of the screen for a moment.
Visible crew/equipment: When Matilda makes the pitcher fly up in the air you can see the shadow of the stick that was later deleted and erased.
Answer: He has been receiving and selling stolen car parts.