If a guest is drinking at a residence and had an accident on their way home, could the homeowner be liable for the accident?

There are different standards for commercial vs. residential host liabilities.

Level of intoxication for purpose of arrest is usually nominal.

What liability are you talking about?

If you are thinking of holding a cocktail party or even a back yard Bar-B-Q at your home, you should carefully consider your responsibility when serving alcohol to your guests due to something known as "social host liability". A social host is liable for serving alcohol to a visibly intoxicated adult guest at their home, and therefore owes a duty to the victim of any automobile accident that is later caused by such guest.  The standard that the courts have adopted with respect to this issue is, “where a social host… knew or should have known that his guest was drunk, but nevertheless gave him or permitted him to take an alcoholic drink.”