Start the tape recording early as not to cut off the beginning of the talents scene. Tape is cheap, use it. Try recording a full 5 seconds before you even start the countdown to cue your talent. In the same vain, let the shot run long after the talent is done. You don't want the camera to back up over the end of your last shot.
Many cameras act differently that way.
Also, many magical moments were caught because the camera person had the patience to wait after the scene was over. Try not to use unnecessary zooms live in the video. It looks so . . Establish the shot then cut to a close up or throw a medium shot in the middle. Never shoot into the light source unless you are purposely going for the witness protection program look.