If it is the case that a screw was sucked into the #2 intake runner, and from your description, then maybe you got really lucky and it's just jamming the intake valve open, thus no compression on that cylinder. I would at least take the upper intake off and see if you can look down there. If not, remove the lower and be sure. Go from there. Good luck.
p.s. if this guy's so intent on it not being "his problem" i'd consider doing a lawnjob in his front yard not "your problem"
