"The argument was due to someone farting," Richard McBride, 53, told police.
McBride and his girlfriend Sandra Stoner, 55, said they were drinking at the bar when an unidentified man punched him in the face after they argued about a fart.
According to Officer Igor Kasyanenko, surveillance footage showed Stone get out of her seat to approach another woman, "getting in her face in what appeared to me as an aggressive manner."
The unidentified man attempted to get between Stone and the other woman, when McBride pushed the woman. The man turned and punched him in the face.
McBride suffered a dislocated shoulder during the scuffle and was treated at Lower Keys Medical Center.
The unidentified couple left the bar after the altercation, but McBride signed a release form and expressed that he was not interested in pressing charges.
Sloppy Joe's bears the original name of a bar frequented by writer Ernest Hemingway while he lived in Key West, though the original location, called Captain Tony's, is a half-block away. Historians say he drank at both locations, and likely a few others in Key West.