Alamo Rental Car Enterprise Holdings Alamo called said that my son hit a rental car in California and his ins paid part of the bill the rest is his.My son lives in Hawaii and was their when this supposely happened. The ins.co. they said St. Loius, Missouri

The OP stated it was NOT sonny's insurance who paid, but another insurer. The problem is that insurer aside, his name got into this as the offending driver. As far as that goes, you're advise is valid - there may be some identity theft, or, more likely, wrong identity involved here. Maybe someone with same name.

If your son wasn't in the accident, or California, why did his insurance company pay anything? 

If your son really wasn't in California, then he should suspect identity theft. Someone had his driver license number and insurance card.

There had to be a police report showing guilt, and a driver account for the insurance company to pay. 

This isn't a rip off report on the rental car company. IF there is a rip off look to your sons insurance company (That you dont name) who paid without verifying he was the driver.