Long discussion pointing out that force against peaceful individuals is wrong, etc. with stastists defending such force (using some of the other fallacies in the list).
Statist: Well, I suppose we'll have to agree to disagree….
Often the statist will conclude with both parties will "just have to agree to disagree" or similar after a drawn out debate where their defense of the state and harm against peaceful individuals has been found wanting.
The problem with this seemingly congenial note is that it assumes the discussion was a mere difference of opinion—as though those who oppose violence against peaceful people are on equal moral, economic, and logical footing as those who favor mass organized extortion and enslavement of millions. The existence of government, and more generically, all initiated violence and threats, is necessarily immoral; and there is no moral equivalence between doing such harm and refraining from it. Attempting to whitewash the discussion as if both were the same and thus both disputants were morally equivalent is dishonest.
If "agreeing to disagree" is your goal then that still means you must accept voluntaryism, because it alone allows for me to disagree with you without harm, whereas the government "solutions" of the statist gives me no say and are imposed by force.
If this reasoning were applied to battery, it would not be considered acceptable: "Oh, you don't want me to beat you? But I do want to beat you! I guess we'll just have to agree to disagree… while I beat you to death, of course." (DBR, based on comment by Benjamin Richards)
"It's just your/my opinion"
Oh god, I hate it. The same thing with "It's just my opinion!!!" Um, your opinion is wrong. You can't spout off copious amounts of bull and then claim it's your opinion like I'm not going to deconstruct all the idiocy you just vomited in my direction. —Joey Rodman
If it's "just your opinion", and you're not claiming it's right, wrong, or even useful, then why bother, as you already believe it's not a positive contribution to the discussion? No, you contributed it because you thought your addition was correct or useful, so stand behind it. And if you're not sure about something, ask questions; don't vapidly assert.
It is no crime to be ignorant of economics, which is, after all, a specialized discipline and one that most people consider to be a ‘dismal science.’ But it is totally irresponsible to have a loud and vociferous opinion on economic subjects while remaining in this state of ignorance. —Rothbard
You don't have to know about everything; but if you don't know, don't claim to know. It makes you appear foolish; there's always someone that knows more about the topic than you.
On the other hand, if I explained something from first principles, using logic and sound reasoning, then it is not "just my opinion"; it is fact, or theory, and if you believe an error has been made, it is incumbent on your to identify a fallacy (error in reasoning) rather than claim that the rational case that has been built is mere unsupported opinion.