There is no doubt that this is a serious academic misconduct, and it will certainly not be widespread in colleges and universities. Whether it is exposed or not is another matter. I think if it were me, I would talk to the teacher himself about it, but it's not the kind of communication that I intend to fight for a larger foe. It seems irrefutable to me, but I'm afraid the evidence is not enough to really explain the problem. It is irrational to make the question public, but according to my own values, it is worthwhile to ask it in private. Young people always want to fight for breath. The reasons are as follows: consider the worst case first. Just a professor, not his own boss. Anyway, I'm just asking, and I won't get him into trouble. After the big deal, we will not communicate with each other. Maybe he didn't know until he asked. Then you did a good job.