In: Economics
As the professor was Canadian, he is one who is practical in nature. He is one who would be more comfortable in his personal space. Although carrying an informal nature, being a Canadian, he is very formal in the class. He doesn't like students coming late and interfering in between despite telling them to sit quietly. Another trait of professor since he is a Canadian is that he prefers being invisible in the crowd and despite him telling his students to behave, their ill behavior affects him poorly.
On the other hand the students at the South American university are much loud and free minded. They do not care much about classroom rules and rather find it happening in disobeying rules so that they can get fun from it.
The students purposely gave reason of late coming related to family issues because they knew that involving family in between would leave them unpunished and the professor would also not say them much.
It is because of cultural differences i.e. calm and private culture of the professor whereas, loud and open culture of South American population that there was such problem in the class.