In the age of The Great Google Machine there is no excuse to not prep and do 5 minutes of research for every interview you do. In a light-hearted local interview it doesn't seem like a big deal... although this one is pretty insulting to the interviewee...
But on a bigger level this no-research thing is scary because there are so many media-faithful idiots blindly swallowing every over-sensationalized headline that is churned out without a real fact check.