Visible crew/equipment: When the crazy woman who said that Edward comes from hell leaves the backyard, you can see the reflection of a crewmember on the left side of the window.
Visible crew/equipment: In the scene where Winona is running into the mansion and up the steps, right before the shot changes, you can see what looks like part of the crew on the left banister by the bottom of the window. (01:28:20)
Answer: If the robbery had been successful, Jim would have been able to accuse Edward of robbing the house with his friends backing him up. Jim probably would have kept the car at a friend's house to avoid suspicion. Since the house belongs to Jim's father, nobody would question him going inside. If Jim and his friends tried to rob someone else's house, there would be the chance that somebody would be home or that a burglar alarm could go off and alert the neighbors and the police.