It's an intriguing question; and at one community college in Mississippi, an answer might be needing soon.
Later today (specifically around 2:05 EDT), I'll be on KDKA Radio in Pittsburgh to discuss this issue.
Without giving away too much of my argument now, I believe an instructor cannot punish a student for swearing -- especially if the words are an act of frustration. (And let's face it, all of us have uttered some combination of "the magic words", as I like to call them, at inopportune times. A sincere apology follows, and we should move on.) And in the Mississippi case, frustration appears to have boiled over. (Click here for the audio from the student's disciplinary hearing.)
But we begin to enter murky terrain when the instructor has to determine the intent. And we enter deeper challenges when we need to evaluate an exchange between students inside a classroom.
There is at least one Supreme Court case that is important to remember. In 1971, the U.S. Supreme Court, in Cohen v California, ruled that states cannot censor public speech or expression so as to ensure society is not offended.
Writing for the majority (the vote was 5-4), Justice John Harlan wrote:
"Surely the State has no right to cleanse public debate to the point where it is grammatically palatable to the most squeamish among us. Yet no readily ascertainable general principle exists for stopping short of that result were we to affirm the judgment below. For, while the particular four-letter word being litigated here is perhaps more distasteful than most others of its genre, it is nevertheless often true that one man's vulgarity is another's lyric. Indeed, we think it is largely because governmental officials cannot make principled distinctions in this area that the Constitution leaves matters of taste and style so largely to the individual."
I'll likely update this post after this afternoon's interview.