Visible crew/equipment: When Roy and Johnny are driving in the squad, while discussing Roy's last phone call from Susan, Johnny's lack of tact, etc., and particularly as they're being dispatched to the "possible maternity case," in every shot facing Johnny pay attention to the window behind the guys, because we can see a crew member's right hand, wearing a ring, who's holding a rope while he's riding on the back of the squad.
Visible crew/equipment: When Roy and Johnny are with 110 and are on scene at the downed airplane, as they remove the pilot from the aircraft, the silver fire starting canister used for the stunt is visible under the plane, before it becomes engulfed in flames.
Other mistake: When Roy gets off the phone and heads to the squad, Johnny follows him wanting to know who he was talking to, and after Roy tosses Johnny a rag to help wipe down the squad, we hear the dispatcher ask, "Foam 27, what is your location?" but subtitles read, "Phone 27, what is your location?" Subtitles from Universal Studios 2010 DVD.
Continuity mistake: When Roy and Johnny are at the construction site with the guy who wants to jump, before Roy walks over to him we see the pompier belt around Johnny's waist has the carabiner hook to his left and the double tongue buckles to his right. Then when Captain Stanley tells Johnny to try and get to the guy from the other side, Johnny's belt is now around his waist the opposite way. In the following shots his life belt flips around a couple more times. Note that their pompier belts have at one side double leather straps which are the two tongue buckles, and the other side has a single strap of leather for the attached carabiner hook.
Audio problem: At the site of the crashed plane, when the trapped pilot screams, "Help, I can't get out, the doors are jammed," his mouth movements do not sync with the words we hear. Then once he's out, it happens again when he says "I guess I'm a little shook."
Continuity mistake: When Roy and John are with Boat 110, after the Harbor Patrol cancels their incident response, we hear that Engine 110 and Engine 58 are dispatched to 'aircraft down' and Boat 110 heads there as well, but when Boat 110 reaches the shore, we see an engine and a squad behind the airplane, just before more of 110's guys appear.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy