Without getting too much into who was the bad guy (the pitcher is almost always the bad guy) this post deals with responsibility in a court of law.
Manny Machado and Yordano Ventura had a fight. Machado punched Ventura in the face last night in Baltimore, where Machado is the 23 year old star of the home team. Ventura is a volatile 25 year old pitcher who is on the downside; he has only 370 SO in 427 career innings and is not worth the trouble he's caused in similar incidents, including one in April involving Mike Trout.
Billy Martin and Jim Brewer had a fight. Martin punched Brewer in the face August 4, 1960 on a Thursday afternoon (they were all day games back then) in Wrigley Field in Chicago. Brewer was a 22 year old rookie pitcher for the hometown Cubs in his fifth major league game, fourth start. Martin was the 32 year old former Yankee known for brawling, banished to Kansas City then Detroit, now Cincinnati. Years later as a manager Martin became known for sucker punching more than one person, including a couple of his pitchers; Martin never learned.
In both cases the pitcher got punched, which is usually a good thing. It's just dumb luck that the pitcher did not kill the batter he deliberately tried to hit with a baseball.
It's also just dumb luck when one person punches another without causing serious damage.
So, we have two pairs. In one there was serious damage done. There was also an unforeseen consequence: legal action in a court of law. Yes, outside the jurisdiction of some ridiculous league.
Brewer was involved in an on-field altercation with Billy Martin on August 4, 1960. Brewer, then with the Cubs, brushed back Martin, then with the Cincinnati Reds, with a pitch in the second inning of a game at Wrigley Field. Martin threw his bat at Brewer, who picked it up and started to hand it to Martin as Martin approached. Martin punched Brewer in the right eye, breaking his cheekbone. Brewer was twice operated on for his injuries, and Martin served a five-day suspension. The Cubs and Brewer sued Martin for over $1 million for the loss of Brewer's services,but later dropped their case. Brewer, however, pursued his, and in 1969 a judge ordered Martin to pay $10,000 in damages.
In 1969 Billy Martin was in his first season as a manager. His team was the Minnesota Twins, whom Martin managed just that one year.
That SABR bio has additional information with mitigating information on Martin. Both accounts, however, indicate that Martin threw a sucker punch. The SABR bio also mentions this during his one year as Twins manager:
... a well-publicized fight with pitcher Dave Boswell, a twenty-game winner, outside of a Detroit bar in early August...
Martin could have seriously injured Boswell, too. You just never know. More from the SABR bio:
During his tenure as a major league manager, Martin’s off-field exploits were legendary, getting into fights with team officials, bar patrons, a cab driver, a marshmallow salesman, and two of his pitchers.
Throwing punches and throwing baseballs at people can have tragic consequences. Better to avoid such things.