Could they have, you know, double checked it? Yes, obviously. But they didn't.
I agree that this story is more about the incredible incompetence of the police involved than flock attempting to record everyone and everything, but flock giving the police an excuse to stop looking and arrest an innocent is by no means irrelevant.
- Does anything connect this vehicle to the accident?
- Did it look damaged; as though it had been in a crash?
- Did it look like it was fleeing or driving erratically?
- Was there anything suspicious about the vehicle or the driver?
Police would have deemed the photo irrelevant and moved on. But that didn't happen in this case.
Their failure to do so doesn't have to do with source of the image (Flock, shop CCTV, dashcam), but with their inexplicable lack of rigour.
Can you give an account of the lack of rigor, or is it some kind of holy mystery?
Their conclusion (after 5 minutes) would have been (obviously) that there’s not so much as a strand of chewing gum connecting the car to the accident, or making it stand out from dozens of others, and they’d promptly get back to searching for the car that actually was involved.
But the question is why it didn't happen. Because that is not what happened.
The answer is that it's flock, and that's the point you're "inexplicably" ignoring.
At no point does a cop have to look at the photo(s), the timestamps, confirm the plate, see if the person who owns the car is driving it, or see the dozens of other cars in that area at the time that should also be of potential interest. They enter the query and get a single answer so obviously accept it as likely perpetrator.