When the car goes over the cliff, there is no water where it landed, only rocky terrain. When Poncherello and Nelson return to recover the diamonds, there is a creek next to the cliff base. No rain was shown in the interval between the two events.
After the girl comes in off the ledge, Poncherello says the female CHP officer will take her home to her parents. Suicide attempts are illegal in California and she would at a minimum be evaluated by a psychiatrist to determine if she was a danger to herself or others.
After apprehending the camera bag thieves, Poncherello tells Nelson he called the LAPD to pickup the suspects and he's taking the bag back to the photographer. The bag would be evidence and would not be returned right away, especially since another agency was working the crime.
After rescuing the girl from the ledge, Poncherello gives Getraer a laundry list of investigative tasks regarding the photographer. CHP patrol officers do not perform this type of investigation, and CHP supervisors certainly do not perform it at the direction of their subordinates.
When Ponch sees the person on the ledge from the street, he says, "It's Sheila!" yet in a subsequent shot from street level, it's impossible to make out any features of the person the ledge. Sheila is on at least the tenth floor; how can Ponch identify her from that far away?
When Ponch goes on the ledge to talk a girl off it, she slips as he brings her in. When he is pulling her back up onto the ledge and into safety, you can see the harness and rope holding the actress to ensure she doesn't fall.
The color of the Mercury Cougar changes after it goes over the cliff, indicating two different cars were used. Also, the gas tank is missing from the car that went over the cliff, a standard safety precaution for crash cars.
When Ponch is about to deliver a baby in the back of the camper, he tells Nelson to call the paramedics. He says the paramedics would do the rest. The emergency team that arrived was the ambulance attendants. There were no paramedics. Los Angeles County paramedics are also a rescue unit. They do not have an ambulance. An ambulance is dispatched separately.
O'Brien intentionally allows the car to go over the cliff to conceal the diamonds from the officers that had stopped him. Since the crash was witnessed by Poncherello and Nelson, they would have written a crash report and had the car removed and inventoried.
The car that goes over the cliff is a light green Mercury Cougar with a black interior. The car in the junkyard is a darker green Chevrolet coupe with a light green vinyl door panel, however when the diamond container drops out the door panel shown is blue carpet.
Before the car goes over the cliff Ponch tries to open the locked door. Since the driver's window was down it would have taken him about a second to unlock and open the door and jump in to apply the brakes preventing it from going over the cliff.