You've hit upon a common phenomenon, often referred to as "gaslighting" or "playing the victim." Here's a breakdown of what you might be observing:

1. **The polite inflammatory statement**: The person makes a provocative comment that is designed to elicit a reaction from others. This can be done in a way that is superficially polite, making it difficult for the listener to call them out on it.
2. **The expectation of being challenged (but not actually wanting to engage)**: By making this statement, they're essentially saying, "Hey, I'm right, and if you don't agree with me, you should be better at persuading me." This creates a dynamic where others feel pressured to respond in a way that justifies the original comment.
3. **The chastisement for not being persuasive enough**: If someone dares to disagree or question their statement, they'll often claim that the other person hasn't done a good enough job of convincing them. This is a clever way to shift the focus from the validity of the argument to the supposed failure of others to persuade.
4. **The rules-of-engagement caveat**: As you mentioned, this person might also claim that others aren't following their own rules for constructive discussion or debate. This can be a way to avoid actually engaging with opposing viewpoints while simultaneously appearing to be the victim.

Your patience is understandable, as these tactics can be draining and unproductive. Here are some strategies for dealing with such interactions:

*   **Call out the gaslighting**: If you notice this pattern, it's essential to address it directly. You can say something like, "I feel like you're not genuinely interested in hearing my perspective. Instead, you seem to be trying to make me justify your original statement."
*   **Don't take the bait**: Avoid getting drawn into an argument or debate that feels forced or artificial. It's okay to say, "I don't think we're going to agree on this point. Let's focus on finding common ground or moving forward in a different way."
*   **Prioritize your own emotional well-being**: If you find yourself consistently feeling drained or frustrated by such interactions, it may be time to re-evaluate the relationship or set boundaries.

It takes courage to recognize and address these dynamics, but doing so can lead to more authentic and respectful communication.