Hiya! He was drunk on stage many times, on almost all instances it just added to his charisma (ex.: Syndey '87) however when he was really really drunk he started being sloppy. Check out Rio 1990 live where he fell on stage 7-8 times (only one was caught on camera), he made several mistakes too. I also remember hearing him make mistakes on KTF rehearsals. For some reason Jon also just didn't like him :(