In the opinion of English historians, Van Gogh's ear was cut off with the sword of his friend, Paul Gauguin, during one of the drunk parties, when they were fencing in jest. Frightened with the blood, Paul Gauguin ran away, and Van Gogh didn't see fit to explain to anybody the real cause of the incident.
Afterwards Van Gogh wrote in one of the letters to Paul Gauguin something like the following: "… if you keep quiet I will also keep quit…"
Who knows… Anyway, Mike Tyson was yet unborn at that time…