I am really surprised at your position on this. There is no gray area here in my opinion. The person that left a hit and run accident was wrong. I would tell that person to admit it themselves or I would do it for them.
My 22 year old daughter just called me last Sunday to tell me the wind took her car door out of her hand and door dinged the vehicle next to her on campus. She called me to tell me she left a note on the car with her information, and wanted to let me know in case we had to get our insurance company involved.
Accidents happen. Dishonesty is a conscious decision.