Future attorneys are taught in law school to never ask a witness a question they don't already know the answer to. On Saturday, CNN's Don Lemon learned this lesson the hard way.

Well after President Obama finished his speech in Ghana, Lemon was speaking live to correspondent Nkepile Mabuse who was reporting on location.

When Lemon asked whether the warm reception Obama received upon his arrival Friday was unprecedented, Mabuse caught him quite off guard with her response.

Pay particular attention to Lemon's body language when Mabuse says, "It's not unprecedented. When President Bush was here, you will remember, in February, there were people who were drumming, there were dances, and President Bush joined some of them" (video embedded below the fold with partial transcript, h/t NBer Jon):