Those ball joints can hide TJ. When they are real bad you can tell just by moving them. When they just start to go they get loose or "sticky" under load at loaded height. A tough thing to duplicate. If there are miles on them, I wouldn't hesitate to refresh that area anyway. Did your Alignment guy check the track on all 4 wheels? If it isn't tracking straight you will definitely fight that also. He should have a reading for the track if he did a 4 wheel check.