To those who ask: It is important to recognize that there are many people who ask questions because they want to understand – which is something that should be encouraged, and there are those who aren’t really asking, but are arguing. The difference between questioning and arguing is enormous.
To educators: Many good educators are not qualified to answer certain categories of questions. Invalidating a question or giving a wrong answer are both unacceptable. A mechanech(es) should either research the topic and get back to the student, or help the student get in touch with somone who is qualified to answer the question(s).