Visible crew/equipment: When Johnny jumps from the third floor ledge onto the lifenet, in the shot of his actual jump we can see a cameraman wearing jeans at the bottom left corner of the screen, who's holding a handheld camera shooting footage while lying on the street. The angle of that footage can be seen just as Captain Stanley shouts, "Gage, you first," and also when they walk the lifenet over to their left, before Cap shouts, "Okay, Roy!"
Visible crew/equipment: When Roy and Johnny are with the boy who bit the dog, as they kneel down to get the hiding dog, the outlines of the mic transmitter and wire are visible on the right side of Johnny's shirt.
Visible crew/equipment: On scene at the fire caused by gasoline stored near a boiler, when Johnny and Roy are with the burn victim, the outlines of the lav mic transmitter and wire are visible on the back, left side of Johnny's shirt.
Visible crew/equipment: After Valerie is hit by the car, when Roy and Johnny tend to her, the outlines of the mic transmitter and wire are visible on the back, right side of Roy's shirt.
Visible crew/equipment: During the structure fire, after Roy and John climb out onto the ledge and the fire flashes in the exterior shots, the next interior shots we see shows stacked boxes falling as the fire flashes through the doors. The interior shots are from episode 3x7, "Promotion", during the structure fire, after the security guard is taken down the ladder. We can even see a crew member's hand pushing a lower box which causes them all to fall.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy