My initial reaction to this was: "Yep, glad to see one of those self-entitled students get called out for his disrespectful behaviour by a Professor." But then

My initial reaction to this was: "Yep, glad to see one of those self-entitled students get called out for his disrespectful behaviour by a Professor." But then I started thinking about the way my Professors in college had behaved about this (I went to a university that's regularly ranked among the top ten in the States.) At least in undergrad, specially in massive classes where there are sometimes 100+ students in attendace -- there was little or no backlash against 'dropping in' to a class late. The only condition stipulated by many of my professors was, "Don't ask for permission to come in and disturb the whole class." Even in grad school, the only downside to coming in late was that you would miss very important material. Nevertheless, none of my professors have (thankfully) thrown me out of class for coming in later than they expected. Students, especially those in the hard sciences and engineering live a fairly stressful lifestyle, with little opportunity for recreation and a nutritious diet. They should be forgiven for slipping up once in a while, whatever the reason ("Shopping around" or just plain "I woke up late because I was up all night doing that assignment")