RPG groups have a unique relationship to rules: we have total control over them. Sure, we choose a ruleset and study it, but it's up to us how much of the rules we ignore or modify, and we can add extra rules as much as we like. Carefully following the system rules exactly as written is an option too.
Many groups leave these choices to the GM. This is common enough that it's sometimes considered a default state --or even considered a mandatory part of the RPG experience. But ultimately Rule Zero is an expression of the entire group's ability to make rules choices: we choose to make the GM the final arbiter. Just like a group can ignore or change a rule about re-rolls or language proficiency, we can also override a system's ideas about Rule Zero or any other rule.
However, some groups won't even realize that these are choices they could talk about. Most other types of structured play have explicit rules that an individual group doesn't get to mutate: nobody cares that you don't think three of a kind should be worth 6 points, and if you can pick up the ball with your hands it's not soccer anymore.
Failing to realize the unique nature of RPG rules, these groups find themselves stuck with decisions they don't realize they have control over. This leads to each player having a slightly different idea about the group's relationship to the rules and no open lines of communication for even noticing this is the case.
For groups laboring under such an unstated and conflicting social contract, problems which may seem like mechanical debates (like whether to ignore boring dice results in favor of interesting events or how to interpret a poorly-worded ruling) or conflicts of personality (rudeness, submission, expectations of privilege) often rise from the fact that some players think we're playing one kind of game when others expected an notably different playstyle. Because they don't recognize it as a perspective problem, each member thinks the other is being deliberately obstructive or is just stupid.
- What can a GM or player do to help mediate a discrepancy in the participants’ desired relationship with the rules?
- What constructive action can a participant take if he feels like the rest of the group isn't interested in giving due consideration to his desired relationship with the rules?
I'm phrasing this very broadly because details specifying the exact nature of the debate tend to attract opinions about who was right, instead of addressing this as a social issue: this isn't about the value of Rule Zero, for instance, because Rule Zero is just one potential symptom of the issue, not the root of it. Whether the discrepancy is between GM and player or between player and player, there's a conflict of perspective that will fester unless addressed.
Please remember the good subjective / bad subjective guidelines, and “kick him out / find a new group” answers will be considered lazy.