This is commonly referred to as Social Host Immunity (for private persons) and/or the Dram Shop Immunity (for commercial vendors: bars, liquor stores, etc.). Therefore, if the evidence is that the person who hit the car your son was in became intoxicated while at his Uncle’s house, if he is an adult, the uncle is not liable for civil damages. Likewise, the liquor store would not be responsible.
There is an exception to this rule – if the obviously intoxicated person is a minor, liability may exist. Section 25602 (d)(1) states that nothing shall preclude a claim against a parent, guardian, or another adult who knowingly furnishes alcoholic beverages at his or her residence to a person whom he or she knows, or should have known, to be under 21 years of age, in which case the furnishing of the alcoholic beverage may be found to be the proximate (legal) cause of resulting injuries or death.
So Trisha I don’t have enough information but, if the drunken driver was an adult driving their own car, most likely, there is no civil liability against the uncle or the liquor store. If the driver was a minor, potentially both the uncle and the liquor store may be liable. You can bet that the uncle will say the driver was fine when he left his home and must have gotten drunk with the vodka bought from the liquor store. The liquor store will claim the opposite.
Trisha, find a good contingent fee trial lawyer who can help you evaluate the facts and liability.