"But really, you could deduce at every point which is the possible position of the nose gear (regardless its elevation). I have made a drawing but don't know how to post it."
if the airplane is not tracking straight relative to the wheels (in a drift, sideways, whatever) the nosewheel can very well be a lot outside the main wheels, expecially considering the lenght of the MD82 fuselage. heavy use of rudder while on the ground will put the airplane in a drift, and produce asymmetrical skidmarks where the nosewheel mark is not in the center of the mainwheel marks, expecially on a non-gripping surface like gravel/dirt. easily reproducible with a car.
in the picture there are probably something like 500 meters between the beginning of the marks and the side road/embankment so the swerving is not so tight at it looks in the picture