School life – Episode Four, Nationality counts

Peter enjoys the writing class of Globe International School (GIS). He loves writing, but he is not good at it, and therefore, he will ask the native English teachers (NETs) of the school to polish his composition before submitting to the writing teacher, whose mother tongue is not English.
The writing teacher spotted some grammatical mistakes, like missing an “s” in the verbs, and some repetitive words in a sentence.
Well, Peter believes he can have a good laugh about these mistakes, and some minor corrections will fix the problems. These are careless mistakes, or probably typo errors.
But the writing teacher is a fussy man, who fails to appreciate creative writing style but think big of himself by picking up minor errors.
“Who polish this writing?” he marked on the composition, before sending a copy to the Big Brother.
He repeatedly asked Peter which NET polished his story, and Peter reluctantly said the name.
“Even junior primary school student will not make such mistake,” the fussy teacher said.
“OK, I’ll fix it,” Peter said.
“Where does the NET come from?” the fussy man asked.
What the heck? Peter thought. How does one’s nationality relate to his English standard and capability?
“He is back home,” Peter replied, trying to divert the topic.
But the fussy man did not back down. “Where does he come from?”
“Canada,” Peter said, of course reluctantly.
“Oh, Canada,” the fussy teacher said, before going away.
Peter believes asking someone’s nationality after something wrong has happened is offensive, insulting, and disrespectful to others, and it may be an offense in some countries.
The school has been established for several decades, and employing NETs for quite a number of years. And the people here still behave like that.