What happens in a auto accident where no tickets are issued and only one person has insurance?

the no tickets and no insurance do not determine liability (who is At Fault for the accident), now if the uninsured driver is at fault then of course a state report can be filed, and they could lose their license, be fined, have to pay for other parties damage etc.......the ins.claims dept will investigate to determine liability for the accident and that person (or ins co) will have to pay for the loss of the innocent........(or percentage of such if not 100% negligent dependent upon state liab. laws)