That is fine if its a team rule. You are mixing up those situations with violations of NCAA rules. You miss class, the coach can suspend you for team rules violations. You skip mandatory team meetings, same thing. Neither of them are violations of NCAA rules. You hire an agent, you take money from a booster, you receive an impermissible benefit by selling your autographed Jersey for free tattoos, those are all NCAA Rules violations. Different rules for different factual scenarios.
I'm not sure what you do not "get". If a violation occurs, the institution reports the rules violation. Even if it was the head coach who found out about it. There is no category for "Head coach" versus "Assistant Coach" or "Offensive Coordinator" versus "Head of Compliance". If an NCAA rule has been violated, you notify compliance and the institution prepares a self report to the NCAA. You keep asking for some kind of verification that a head coach was the one dropping the dime on the player. Had Tress done what he was supposed to have done, he would not have called up the NCAA, "Look, this is Tress, I have a violation for you..."
Instead, he should have notified compliance of an allegation of NCAA rules violation. He could have done some sort of investigation first, of course, or just handed it to compliance. What you still don't get is that there is a "duty to investigate". That is separate from the duty to report. Of course, if you do not investigate, then it is far more likely that you will never report...which is sorta the point on the duty to investigate.
What you are saying in demanding a reported case of a head coach "catching" a player is a red herring. The foremost reason is because the "tracking" mechanism of reported violations has no separate box for "turned in by Head Coach". Secondly, it is a false predicate. It matters little who first found it, so long as the head coach knew and passed it on to compliance. How many times has a head coach first found out of a problem from teachers - or deans - or assistants - or girlfriends - or fellow players - or parents - or whatever/whoever? Finding out "first" is unimportant. More relevant is this, how many times was a problem brought to a head coach, and then that coach either investigated and then bumped up to compliance, or simply listened to the story, and then bumped up to compliance?
All we will ever know - usually - is a brief paragraph submitted by the PR wing of the institution saying "University of X sent a letter to the NCAA reporting that it became aware of potential rules violations in the (fill in season) of (fill in year). Coach Y and the University have no comment on the matter and will respond at the appropriate time, but Athletic Director Z reports that the University's internal compliance department became aware of alleged improprieties, that an investigation was performed, and that as a result of this internal investigation two student athletes were suspended."
That is it. That is what happens. Asking for some list of "head coaches who were the only only ones to ever know" will never be forthcoming, largely because most coaches report it like the NCAA rules demand, at least if it is any one of the big NCAA rules having to do with money or agents or academic fraud. They do this out of fear of the NCAA mostly, not moral fiber.
Weed and DUIs and traffic offenses and sleeping late, and losing playbooks, and missing class, and curfew violations all of those are within the coaches ability to handle in house.
Money and agent stuff ain't.