When another open bottle arrived to replace the first, Robert ignored Sonny Boy's warnings and drank it. By the time they began playing again Robert couldn't sing and soon after that he stopped in the middle of a song and left the stage. Robert became very ill and it was clear he had been poisoned. He would die a couple of days later from pneumonia. The bar owner had apparently arranged for strychnine to be put into Robert's drink.
Some reports say the jug of Whiskey has a cake of lye in it.
Either way Robert Johnson was dead at the age of 27. Word got back from Don Law of Vocalion Records after some searching that Robert had died. John Hammond got Big Bill Broonzy instead. When You Got a good Friend. Some of his songs were made hits years later by musicians such as Eric Clapton and Led Zeppelin.