Visible crew/equipment: When moving into their apartment Patrick Swazye kicks the statue to make it swing so they can get it inside. As they are looking at the statue, two moving men cross in back of them carring a mirror and as they pass you can see the director and camera crew in the reflection.
Visible crew/equipment: When Kevin first realises he's home alone and goes into Buzz's room, there is the leg of a crew member to the bottom right of the picture (wearing jeans). (00:19:20)
Visible crew/equipment: When the Red October sub has surfaced to let the crew get off because of the supposed nuclear leak, there is a brief shot where you can clearly see the camera and its filming crew in their tennis shoes on the deck. (01:45:52)
Visible crew/equipment: When a carload of bad guys drives past the front of Seagal's sister's house and riddles the front of the house with machine-gun fire, Seagal quickly slams the front door shut, and you can very clearly see all the stunt charges attached to the door.
Visible crew/equipment: When Ben first arrives at the house, a zombie tries to get in through a door in the kitchen. Ben fights it off and tries to push it out the door. Initially, when he first closes the door on the zombie, the relfection of the cameraman is seen as clear as day in the window of the door.
Visible crew/equipment: When Robocop visits Cain's hideout and sends his car in as a decoy, after he returns to the car, watch the driving shot closely. A wire has magically strung itself across the entrance and attached itself to the back of the car - it wasn't visible from an earlier shot. As the car drives forward it stretches the horizontal wire, and just as a tiny amount of pressure is exerted, the car explodes. Yeah, it's technically a mistake, but I think it's more worth checking out just to see how those tricky effects are achieved.
Visible crew/equipment: When Mel and Goldie enter the salon on the motorcycle, you can clearly see the ramp used to help propel the motorcycle forward, just as Mel comes to a stop.