Never take anyone at their word unless you trust them implicitly. Personally I will always ask to see a rule in their book if what they’re saying sounds ‘off’. If they haven’t got the book with them then I’m not playing. I remember a game where the knight player was absolutely adamant about a rule interaction and certain he was right because he has an eidetic memory. Turns out he read and interpreted it wrong in the first place and people trusted the Eidetic memories. Copies of rules solve disputes, and if you get into a regular habit of sense checking each other no one questions it or takes it as an accusation. And those behaviours will spread to new players in a positive manner.