I mean, the whole article is framed to indicate that the poor grade is what resulted in this mans pursuit to amend the constitution.
The headline is literally "The Bad Grade That Changed The U.S. Constitution"
The teacher goes on to say of herself "You have, just by making this fellow a grade he didn't like, affected the U.S. Constitution more than any of your fellow professors ever thought about it, and how ironic is that?"
The article also insinuates that Watson only began lobbying to change the grade. "Most people would have just taken the grade and left it at that. Gregory Watson is not most people."
