Your story re: Leonard Cohen and bottles reminds of festivals back in the 1980's, when there seemed to be a phase of people drinking from plastic litre bottles (usually cider), refilling the bottles with piss, and then throwing these bottles at the stage. One time I saw someone doing this, but his aim was rather poor, and the bottle smacked into the back of the head of someone stood a few feet in front of him. This bloke, irate at being hit on the head and the piss now splattered on the back of his coat, looked around angrily. Instead of looking behind him to suggest he was trying to see who threw it, the first guy apologised - and the "recipient " of his bottle proceeded to beat the crap out of him, much to the amusement of those stood nearby.