Same vein: the best way to get a knowledgeable person to talk about a subject is to ask an "ignorant" leading question, such as 'Don't they do x with y ?' that

Same vein: the best way to get a knowledgeable person to talk about a subject is to ask an "ignorant" leading question, such as 'Don't they do x with y ?' that has an inaccuracy or just outright falsehood.