pipe to flange, pipe to weldolet, pipe to bend, pipe to trunnion
Did you get this done at a professional shop? If so take it back and make them fix it right. If not tell that guy he has no business working on cars if he causes more problems then before he touched it. If stud missing, person could have lost it, should have told you when you got car back. Or they stripped the stud when putting back on and just put it on good enough to leave the shop, and it fell off while you drove. I would do visual inspection to see if you can see anything out of place from driver side to passenger side. Did the sound start right when you got it back, or was it there before? Could be sway bar links or bushing, or ball joints too, but if it started right when you got it back, something is probably loose, and needs attention. Take it back and ask them to fix for free, if not a shop, find a good friend to help you out so your not out any more money.
If caught, the student would be likely suspended or at least have to serve detentions.
