Continuity mistake: Near the start when Mike's pulling over, the car parks literally perfectly along the side of the road. Seconds later when camera shows him stepping out it's at least 12 inches away from the curb. (00:11:00)
Visible crew/equipment: When Mike is checking his house for intruders, he quickly opens a closet. When he does someone moves to the back of the closet so as not to be seen by the camera.
Answer: The bulldozer could be disassembled, the individual pieces carried down, and then reassembled once underground.
BaconIsMyBFF