In a neighbourhood school where I spent solitary season as a Flexi-Adjunct Teacher, I once relieved an upper Sec Chinese Language lesson.
The teacher was from Mainland China. A student clearly hated the subject and the teacher. He stomped on the worksheet until there was a footprint and then wrote: 中国人吃狗肉 （China people eat dog meat) on it.
He submitted this offensive piece of work.
I do not know my colleague’s reaction to the worksheet.