Some rules do only have one way to interpret them, with other "interpretations" being misinterpretations. Let's take this rule, "When the outcome is uncertain, the dice determine the results." The "when" indicates with no room for other interpretations that the following has to happen before second part of the sentence. So the one way to interpret that rule is that you have to determine uncertainty BEFORE the dice determine the results.
That is actually a very good example of something that is more a guideline than a hard rule (the kind that you have in a boardgame), because it all depends as to how you interpret "uncertain". If it was a boardgame, the writing would be more like "When a creature has 10 hp or more...", but with a wording like "when the outcome is uncertain..." different people can (and have, all along this thread" proposed interpretations of "uncertain" that actually show that this is way more a guideline than a rule.
"Uncertain" can actually be very circular in this simple sentence, it could be uncertain because you have decided to use dices to resolve it, for example. Or it might be uncertain because it depends on simple circumstances, on whoever using the skill being at the top of his shape or not, of simple luck, or whether he knows (or not) that what he does is adapted (or not) to the target of the skill, etc. It also might be linked to very "meta" considerations like whether you are Rolling with It or Ignoring the Dice (The Role of Dice), how much you believe in player agency being something inviolate, etc.
And especially on this last point, which I've seen being used in this thread, I would like to remind people that it's not something that is ever used in the rulebooks themselves. The only thing there has to do with advice and table rules, nothing hard and fast. So stating that a result is not uncertain because the player will determine the result is for me a really, really REALLY strong example of the "rule" above being twisted into something that has nothing to do with the RAI, just because some people strongly believe in a principle that is far from being universal and is actually not supported by any of the rules or even guidelines.
So no, that "rule" is actually much more of a guideline to me... Which does not mean that you are wrong, but that there are so many ways to play the game that statements like this have actually a high likelihood to be not applicable to at least some of us due to the extremely open nature of the game.