For the long femurs, Front Squats with enough weight to counter the "forward lean" and use the RKC/pwr to people squat where you pull the ass down with the hip flexors. Using this during process during a KB class I was at, almost got my ass to the ground.
With the disk, extension and decompression activities following all loading exercises. The issue you are describing sounds more like an SI joint (can't tell without assessment but?), he was likely loading one leg a lot more than the other. Single leg hip flexion/extension activities followed by isometric adduction will usually clear that stuff up.
Hope that helps.