Didn't happen to me but I saw my good friends and co-club organisers, Staff Folk, get onstage at a Methodist Hall at which they had been booked. On opening his guitar case and seeing about a dozen cans of Guinness cascade over the stage, Dave realised he had forgotten that the Guitar was already on stage and he had filled the case with said Guinness to get around the drink ban:-)

Luckily everyone saw the funny side.

Cheers

DeG