In my fading memory of Davie's chapter on the 747:
- The wing gear has considerable vertical travel. If only one wing gear comes down, you have to retract it as it will otherwise keep coming down and tip the a/c.
I suspect the wing gear came up on its struts as it contacted the berm while the body gear had less travel. Add to that the flex in the wings as they generate [insufficient] lift. These factors cumulate in less loading on the wing gear.
The removal of the structures on the top of the berm in the path of the wing gear show that it was down there. Note that the nacelles did not take out anything on top of the berm which further indicates that the wing was developing some lift.
- The body gear can pivot in taxi turns -- this along with progressive deformation of structure may explain the divergence in the tracks.