According to Robinson's friends, he underwent a personality change after his injury. Many of his acquaintances recalled that he became more withdrawn. In a later interview, Robinson admitted he had started using cocaine in 1985. In January 1986, a few days after Tennessee's victory in the 1986 Sugar Bowl (which Robinson watched from the sidelines), he and his roommate, former Vol fullback Kenneth B.B. Cooper, were arrested by Knoxville police in a sting operation. Robinson was subsequently charged with taking part in the sale of 30 grams of cocaine. He eventually pleaded no contest to lesser charges, and was sentenced to nine months in prison.