Looks like the smearing happened during our scanning process. Here is one of the original frames (EXR format).
http://www.thestarwarstrilogy.com/starwars/file.axd?file=/2016/01/StarWars.Frame.00022792.zip
As you increase the gamma / brightness the smearing becomes more apparent…
Could this also be the reason why there seems to be a light band on the right side of the screen throughout the movie?