Continuity mistake: When Gail, Laurie, and Pete realize they forgot Melinda, Johnny is wearing his leather jacket when Roy says "Look, it's a boy," but in the next shot Johnny's jacket is gone when he asks what happened.
What's a Nice Girl Like You Doing...? - S7-E7
Visible crew/equipment: After the last rescue it cuts to Roy as he says, "We'll catch you all a little later," and when Roy walks away we can see the actor's T-mark on the floor, where he was just standing.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy