Most esoteric arguments I have seen end up being where both parties think they know something about the rules but have different, non-overlapping areas of the rules they remember (and even then, only vaguely).
Most of the time people stick to some subset of the rules they have seen used before, but every now and then they get annoyed when someone else seems to be taking some liberty and they challenge it; at best this is because they have some vague memory of that being wrong, but more often it is because it feels like it should be wrong.
(My favorite example of this was one time I saw an eight hour long meeting get ground to a halt as the chair of a student government asked the supporting staff member to "do me (her) a solid" and search their old minutes to see what they did the last time they had this same argument, as they had all determined later that whatever they had done was wrong.)
On the "parliamentarian"... if you even have a "parliamentarian" (omg lol) you probably are in the category of group where Robert's Rules of Order might have even been designed. Most governments (not by area serves but by count; these are all the small districts and cities) are at most five elected or appointed board members, and they have access to a city/general manager and maybe (if they can afford the luxury), a lawyer. (My government decided we can afford access to a lawyer every other meeting. I have seen many governments that never have lawyers available during meetings.) The idea that any of the governments I am a part of would have access to a "parliamentarian" feels just absurd to me... :(.
("Source": I am an elected government official who was further elected by all of the local special districts to serve on the meta-government that creates, modifies, and destroys other governments; and I am further the kind of person who then--with glee--attended both the big annual conferences for my kind of government as well as of all of the meta-governments to talk about all of the different kinds of government ;P. I work with a lot of governments, and I'm seeing everyone migrating to Rosenberg's Rules of Order.)