it was just another case for Sherlock holmes. He was in a bar, eaves dropping to try and find clues. The bar owner was jumpy and suspicious, interrupting Holmes work a lot with his questions and demands for Sherlock to stick his nose out of his business..

Sherlock being a persistent and determined man....didn't. this led to a bar fight which led to you, a passerby, saving holmes from a possibly life ending injury.