Revealing mistake: After Johnny's line gets snarled while testing Wally's equipment at the studio, when Roy lowers himself on his own line wearing his lifebelt, we can see the added carabiners that are attached to the lifebelt which go down into Roy's pants, and are presumably attached to the extra support the actor is wearing under his pants.
Revealing mistake: At the studio, in the overhead shot just as the squad is about to reach the building where Johnny will be testing Wally's equipment, the 'Black Tower', which houses Universal's executive offices, is visible in the background, and then in the roof shots when each of the guys repels down individually, the Sheraton-Universal is visible in the background.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy