Criminal law, traffic matters, DUI, assault, theft, fraud
Your friend should ask themselves, "What's the worst that can happen".
My thoughts are that if they make a claim, and complete that honestly, the worst that can happen is that the insurance could refuse to pay. But they may also receive the write off value for the car.
The police may believe it was due to speeding, but that is not proof, I could have been due to a patch of oil on the road, etc, etc.
If your friend was not speeding they could fight the ticket in court.