This doesn't happen very often — Terri Pederson, "Them's fightin' words: Grammar dispute becomes brawl", Beaver Dam Daily Citizen 7/8/2014:
A 27-year-old Fox Lake man was charged with battery stemming from a fight that occurred at Tower Lanes in April. [...]
According to the criminal complaint, an employee of Tower Lanes had pointed out Gubin and another man who had been allegedly fighting in the business. The 35-year-old victim had facial injuries and injures to his hand.
He said the fight began over a disagreement over grammar as well as their views on sports teams. He said Gubin had kicked over his chair and then struck him with a closed fist several times and kicked him. The victim originally did not press charges but called police a few days later to say he had received substantial injuries during the fight. When he was kicked on the left side of his face, he suffered three tears to his retina that needed surgery to fix.
Gubin was ordered to not have any violent or abusive contact with anyone. A review hearing was scheduled for July 23 and a preliminary hearing was scheduled for Aug. 21.
The article doesn't specify what sorts of "disagreement over grammar" or "views on sports teams" were at issue. Perhaps these details will emerge as the case proceeds through the judicial system.
The comments, of course, are argumentative:
nuzzo: If the guy's grammar was as bad as your headline writer's, I can see why it came to blows.
"words" is plural, so "Those are fightin' words"
Chan: And your sentence has a subjunctive phrase that should be written "if this guy's grammar WERE as bad….."; it should not read "if this guy's grammar was as bad…."
Wangchung: Who cares dude got rocked!
The most recent comment:
RobertWReif: “He said the fight began over a disagreement over grammar….” So about what, precisely, did they disagree? I hope it was actually “over grammar” and not simply syntax or even diction. I was once involved in a real donnybrook regarding the use of “continual” as opposed to “continuous.” However, this was merely a matter of diction, so it never came to blows.
The worst knock-down-drag-out fisticuffs I ever engaged in concerned when to use “who” or “whom.” That, of course, was completely warranted because it actually pertained to grammar. The fight was with Sister Alphonsine, my eighth-grade teacher at St. Pat’s. It was essentially a draw. Were she still living, I do not doubt that I could whup her now.
At one point in my life I had several friends for whom bar brawls were a favorite form of recreation, but I don't recall grammar ever being used as a casus belli. I can't even think of any literary or cinematic examples, despite the prominent role of brawls in 19th-century boys' literature, 20th-century noir fiction, cowboy movies and their successors, …
Update — There's some additional information about the sports disagreement in Collen Kottke, "Heated exchange between football fans results in battery charge", Fond du Lac Reporter 7/9/2014:
Gubin told police that he was at Tower Lanes in Beaver Dam on April 17, 2014, when he got into an argument with a 34-year-old man over the views of Green Bay Packers and Chicago Bears fans, as well as a disagreement over the use of bad grammar, during the verbal exchange, according to a criminal complaint.
But there's still no information about the point of grammar involved.