Here's what I did. In the track info area to the left of the time line, right click and select duplicate track. On the bottom track create a mask that cover the left interviewee. On the top track, select pan-crop. In the pan/crop window right click on the image and select flip horizontal. Now, go to track motion on that track and position the image properly. You now have the guy on the left favoring the center of the screen. Make sure the cursor in pan/crop and in track motion is at the beginning of the clip when you do both of the above.