First State Bank of Sinai v. Hyland
South Dakota Supreme Court
399 N.W.2d 894 (1987)
First State Bank of Sinai (plaintiff) sued Mervin Hyland (defendant) to collect on two promissory notes he co-signed with his son Randy, whose share of the debt had already been discharged in bankruptcy. Mervin claimed he had no memory of signing the notes because he was intoxicated at the time, and evidence showed he suffered from ongoing alcoholism serious enough to require involuntary hospital commitments during the same period; but the same evidence showed he was still able to transact other business -- paying for farm goods, buying livestock, and driving -- while not under the influence. Mervin also received multiple bank notices that the notes were fully due but never acted to disaffirm them. The trial court ruled for Mervin, and the Bank appealed.
Whether, under South Dakota law, voluntary intoxication may render a contract void or voidable where it is sufficiently shown that the individual was entirely without understanding at the time the contract was executed.