Hi,
The surface selection is sometimes tricky with mesh grabber, but there is an easy fix. Hide the object for which you actually want to modify the surface, and using the surface selection tool, select the surface of the model that was distorted. The activate the meshgrabber tool and display the tool settings pane. You should see a "reset" button on it. If it is not active, then there was no modification done on that surface and you may need to find another surface to fix. If it is active, just click on it and validate the confirmation dialog.
You can show your other object/prop again.
My workflow with Mesh Grabber is this: always have the scene AND surface editor panes active while using it. If either of the active item changes in either pane while i'm working with mesh grabber, I go back to the surface selection tool and reselect the surface to modify, and back to mesh grabber.