From personal experience:
Some people don't understand the concept of private settlement.
Other driver swerved into my lane while trying to avoid a pair of decelerating vehicles (both switching into same lane) infront of him.
He clobbered into my driver's side door, side mirror, front fender, front bumper.
His damage was left side mirror, front fender, front bumper, wheel rim.
No injuries.
He immediately offered to settle the damages privately.
I told him I would have to check with my regular workshop to get an estimate on the cost of repairing the damage, but yes, private settlement was ok with me.
We exchanged details (and took pic of the damage) and I requested for HIS in-car camera footage.
He agreed.
He WhatsApp the video footage a short while later, after we left the accident scene.
His footage clearly shows he was travelling too fast to avoid rear-ending the pair of vehicles infront, and changed lane (into the one I was driving in) without checking his blind spot.
He conviently cut the video footage just before it shows any impact with my vehicle.
I go to my workshop and they quoted me for the repairs.
I inform him, he say - Why so expensive? Go to HIS workshop.
Okaaaay.
His workshop is some far away place and is even more expensive.
He then ask me to split the repair cost.
Huh
Private settlement become now I'm-to-foot-the-bill-for-an-accident-clearly-caused-by-you?
I had already informed my insurance about the accident and his offer to settle privately.
They saw HIS video footage and laughed

- Really arh? He actually sent you HIS own video footage of him causing the accident?
End result is still being handled by insurance.