Fallacies of Generalization (Sweeping Generalization)

I would also like to share about a blog entry I came across last week written by a teacher friend of mine. This friend of mine was distressed and disappointed after a statement made by one of her students in class. 
Let me first give a brief background of her students, her students consist of international students that are from Saudi Arabia, Yemen, Iran, Sudan, Korea, Japan and China. 
Her class generally consists of well-behaved students who are in their teens to late forties. However, there is also a particular group of students from Iran who are always rebelling against the rules that were set on the first day of class. Having being concerned over her students’ learning and growth in acquiring English as their foreign language, she constantly reminds and  calls out students who are disruptive, speaks in their own native language in class and often prefers to have small talks with their fellow peers. 
What shocked her the most was when one particular student stood and claimed that my friend hated all the Iranian students with the reason that she only picked on them and not students from other countries.
I personally felt that the particular student had given a sweeping generalization of her teacher. It it fairly obvious, that an unfair and irrelevant conclusion towards the teacher was made based on the thought that only Iranians were often told to behave in a pleasing manner in class thus concluding that the teacher dislikes people from Iran without taking into the account that the students from other countries were very much well-behaved hence the logic that they do not have to be reminded at all.