Just accept that it is a FACT that if someone has acted in a deliberately subversive manner, with planning and forethought, (in this gaming environment)... then it is *factually correct* to call them "not to be trusted" (in this gaming environment).
In the narrow context of "trusting" them to follow PG rules? Obviously they have demonstrated that they will disregard those rules so if that is all you mean then sure, that's a reasonable statement to make under those specific circumstances if you do not extend it beyond that directly observable pattern of behavior. However, your argument has not been that focused or nuanced and has instead been extended to the "player" being inherently untrustworthy as distinct from their "character" in-game. You have been trying to attribute personal tendencies towards being "trustworthy" without considering that for those individuals, disregarding the PG rules may simply be part of "playing the game" and have no bearing whatsoever on other decisions that person usually makes.
It's not really a "fact", it's just an observation about their behavior in that specific context. You might not trust someone or consider them "trustworthy" but all you can objectively comment on is observable tendencies towards certain behaviors. No one can be "trusted" 100% of the time, under all circumstances, and trust by definition is a very subjective concept in many situations. You can't really go around claiming to have "facts" or "absolute truth" when it comes to making a subjective decision to trust someone.
It really is that simple.
Nobody cares if you happen to "not like" this fact, but no amount of words or weaseling will disprove that it is still a FACT.
It's really isn't "that simple".
First, if you want to talk about trust, you need to know what you're actually referring to. Behavior? Intent? Reliability? All of those factors relate to trust and are really different concepts. You are taking a subjective decision to "trust" someone and then extending the concept of their "trustworthiness" as if it were an objective "fact". It is not a "fact" whether you decide to trust someone. It is simply a decision you have made not only based on observable facts but also on your own emotions.
Second, whether or not you personally trust someone is completely separate from their observable pattern of behavior. One (behavior) is directly observable, the other (trust) is an emotionally-laden and therefore subjective concept. Individuals will sometimes continue to "trust" someone long after it becomes clear that their behavior is completely counter to that "trust". You cannot use the concept of "trust" as if it were somehow a "fact" without making a clear distinction between the behavior itself and whether you have decided to trust that person.
I'll give you an example. I routinely treat patients with severe addictions issues in an acute hospital setting. I don't refer to "trust" when I discuss their substance use patterns because it has too many pejorative connotations and isn't a particularly useful concept for various reasons. I do, however frequently refer to patterns of behavior, intent and reliability about whether they have been using recently and their likelihood of relapse. I also refer to various interventions that will minimize this. Whether or not I "trust" them or consider them "trustworthy" isn't really relevant here because I am not basing this on my subjective decision on whether I "trust" them, I am basing it on what I can observe.
For example, I can observe a change in their behavior that indicates they have used a substance, can I detect the presence of that substance with laboratory testing and I can determine if this correlates with what they have told me about their substance use. When these observations are discrepant then I will certainly address that the information they are giving does not appear to be accurate. I do not simply decide they aren't "trustworthy" as a sweeping statement however and I always address each situation individually. It's possible that there is another explanation for their change in behavior, a lab test may be giving a false positive or negative result and an individual may not always realize they were using a specific substance. I still obviously have a sense of "trust" based on these patterns of behavior, but I recognize it as subjective and prone to attribution bias and various other complex emotional factors. My job is not to simply decide if someone is "trustworthy" and use this as a basis for my clinical decisions, my job involves a much more complex understanding of their behavior and decision making.
What you are doing with players who refuse to follow PG rules is taking a very limited observation about a player's behavior in a specific gaming context and are making sweeping statements about whether those players are "trustworthy" or not. You have also been repeatedly characterizing your statements about trustworthiness as a "fact" or "absolute truth". I'm sorry but you can't make sweeping statements about trustworthiness that are inherently subjective and expect anyone else to accept them as "fact" when they are not.