Asking for help creating a mannequin effect from a person standing still.

Here are some of the problems you will face when you move a camera and have to separate an actor from the background and change the timing of their movements.

1. Filling the hole when you remove the actor from the background:
        This problem can be solved if you have motion control cameras so you can precisely match camera movement in multiple shots. If the timing can be reached, you can get a clean plate that allows you to manipulate the actor in the scene easily. Without a clean plate, you are stuck with cloning or patching the problems in the background in some other ways.
   
   
2. Changing the timing of the actor with a moving camera:
        If the actor is successfully removed from the background and you want to freeze the actor's movements completely, the parallax changes from the camera movement will be out of sync with the camera movement. The high-budget solution is to create an accurate 3D model of your actor in the frozen position or to photograph the actor with a ring of multiple cameras the way they did the time freeze effects in the Matrix movies. The only other way to successfully do that is to limit the camera movement to a simple pan, so there are no perspective changes with the actor against the background. All you have to do is separate the actor from the background, freeze frame the actor, then motion track the shot to keep the actor lined up with the original shot, and fix the hole in the original shot with a little cloning.
   
   Without proper planning and execution of the camera moves, the best you can hope for is just to do the separation from the background, background repair, and freezing on a few of the most apparent problems  instead of the whole shot. 

I hope this workflow description helps. If you have already shot the footage and you can share the shot, we can offer some more specific suggestions.

I did something similar for a Discovery Channel show a long time ago where I had to follow a wildlife photographer through the forest, then repeat the shot without him in the scene, so we ended up with a handheld shot walking through the forest with no one in the shot, then the wildlife photographer magically appeared with his camera, raised it up and took a shot of an elk that appeared in front of him. We got the shot of the photographer taking the photo first, then I returned to the starting point of the walk up the trail and shot the walk at double the frame rate so I could match up the timing and the camera movement of the background replacement. I shot the walk up to 4 times and was able to match up about 3 seconds of footage with no photographer in the scene before he magically appeared in the shot. 

You would need to mask them out and then smooth out the motion with Twixtor/ Timewarp/ Time-Remapping, including "freezing" them by lowering the frame rate drastically. You will likely also need to smooth them out with some blur effects so the look "plastic" and twitches in the eyes or mouth area don't give it away. Additional tweaking with distortion effects may be necessary. Hard to say what exactly needs to be doen without seeing the exact footage or some reference frames at least, but you're basically doing a full re-compose and retiming of the shot.

Mylenium