the shimmer was on the top of luke's prone body, the bottom of bens rob and the sleeve on his outstretched hand. it was a twofold issue.
1.) looks like there was a field shift that the IVTC didn't handle right when I did it originally. so that these areas shift left and right for about two seconds.
2.) massive jaggies, again due to the IVTC not coping well with the minimal movement of the subjects.