I think that is an erroneous conclusion, Paul. There have been a couple of long threads on this subject in the past 7 months. I can point you to them if you are interested. Here is my logic from those threads as to why the obligation exists.
True, the rules contain no explicit language requiring self-reporting of fouls. But the rules specify (1) those actions that are fouls and (2) the consequences of those fouls. The rules do not say such actions are fouls only if the opponent or referee is paying attention, or is able to see them, and calls them. So if they occur, they are fouls, and the specified consequences should follow. But the specified consequences cannot occur unless someone acknowledges that the foul occurred. And in some cases it is only the fouling player who is aware that it occurred. Hence, by the rules, he is obliged to call it.
In a refereed match, when a player thinks he has fouled and the ref does not call it, that player has an obligation to inform the ref of the foul. Now, it's possible that the player thinks he fouled when he really did not. [Example -- the ball the player is watching fails to hit a rail and the player thinks he fouled, but, in fact, he did hit a rail with another ball he didn't see.] So the player should inform the ref of the foul he thinks he committed. It is then up to the ref to make the call or not. If the player is sure he fouled and the ref won't call it (example -- he knows he touched a ball in an all-balls-foul match), he can continue play knowing that he fully satisfied his obligation. [Some people might even go so far as to make an obvious, compensatory foul at the next opportunity.]
In a non-refereed match, the obligation is to inform the opponent.