I don’t know how I’m just now noticing all these things, but it looks like there are still some artifacts of optical compositing (or shitty rotoscoping) left in the SE:
JEDIT 2: Fixed it.
That’s normal motion pucture blur and digital rotoscoping (if it were optical compositing, we’d see a black outline around the legs).
The problem with this part of the shot is that you have two overlapping objects that are in motion with film that is moving at 1/48th of a second. Anyone who’s shot a camera in manual mode knows that things get blurry pretty easily under 1/60th of a second.
In this shot you have the camera panning and following the speeder going right and crisscrossing the man who is walking left. With these two opposite motions, you’re going to get some weird artifacts.
Concerning the legs: because of the blur, there is no hard outline separating the two objects, and it’s difficult to cleanly create a matte for the shadow and erased wheels.