Winnifred, you bring forward a very important point in your comment. The best way to diffuse a potentially disruptive situation in the classroom is to remove the disruptive person but to do so in a respectful way to them and to the rest of the class. Taking class time and to showcase the situation in front of peers is rarely an effective methodology. This is also a good reason to always have an assignment you can introduce that can be of value to your students and give you time to handle any situation that could arise. I always have an exercise that was easy to introduce and had value to the students that I could use if I had to break away from the classroom for any reason. I did not have to use them often but when they were needed, I was very glad I had them.
Regards,
James Jackson