Visible crew/equipment: After Johnny and Roy save the man at Vic's party, when they are leaving, the reflections of crew members and production equipment are visible on the orange surface of the ambulance as it drives away.
Continuity mistake: While Johnny, Roy, and Vic try to outrun Charlene inside Stage 3, after heading down the ladder, when Roy opens the door to find Charlene standing there, Johnny's holding the red extinguisher in his right hand and the nozzle in his left hand, but next shot they've switched hands.
Continuity mistake: When Roy and John are talking to Vic at his party, his manager's cigar changes length repeatedly, from short to long and back again, depending on the camera angle.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy