It doesn’t explain it either.
No cop should be that oblivious to their surroundings when they are at a potential crime scene.
Were they parked somewhere where they could not see anyone approaching the vehicle and why would they do that? If there was a call about a possible rape, they should expect a distraught woman running towards the car.
I’m not buying it.
When bad things happen it’s very rarely because one thing went wrong. Tragedies generally are the result of multiple small failures adding up, many/most of them inconsequential in themselves.
Never put something down to ill intent when mere stupidity will do.