Just to clarify, the system doesn’t decide, as a matter of volition, to put an end to the disagreement, and it doesn’t pick one or the other score. It has an internal timer which times out. The status of the board at that moment becomes final. It is unclear to me exactly how this timing system works because things I have been told or read seem not to match my own experiences. So I won’t say anything further on that.
Score cheating happens every day. It is a tiny percentage of the games, but with thousands of games played every day, it adds up. I’m not sure the effect of a reversal is something that could be just “accepted,” which implies a policy decision, rather than a technical issue. Again, to speculate: imagine the cascading effect of a reversal resembling the multiplication of grandchildren at each remove. And imagine if a couple reversals occurred close together. It seems plausible to me that such an effect might well bollix the system, causing it to freeze up or crash.
If this is the case, then the system has a major defect. It would seem to me that delaying the effects (on the ratings of the players) of wins & losses might help to permit reversals without “ripple effects” through the entire field of players. In fact, I really do not understand why people need to have instant (or near instant) updates of their ratings following a game. As far as pairings in a tournament, use “temporary” (i.e. “unofficial”) rating changes to permit continuation of the tournament.