Continuity mistake: When 51's with Cora, the woman who was thrown into the middle of a cactus patch, they lower the ladder horizontally so it's beside her for the rescue, but while Roy treks across the ladder in the next shot of Cora the ladder is nowhere to be seen, then when Roy reaches her we see that it's indeed right beside her.
Continuity mistake: When Dixie walks over to the admitting desk and asks the nurse to stop what she's doing to set up treatment 4, the nurse places the black pen inside the metal folding clipboard and flips it closed, but in the next shot the pen is lying on top of the closed clipboard.
Continuity mistake: When 51's guys get to the roof of the building with the swaying sign, Marco places the silver hose roller on the roof edge, but when Captain Stanley and Stevie's father lean over the edge to talk to Stevie, the second larger hose roller is already in place near the silver hose roller, even though the second one hasn't been brought to the roof yet by Engine 95's guys.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy