Man, that stinks.

I feel your pain. I dropped a screw down the dist. hole while finishing up my motor about two months ago, heard it go into the pan. Did the exact same thing you did, tried to fish it out with a flexible magnet, couldn't get it out, had to take the pan off. When I turned the motor over, it got lodged between a piston and pin, had to wiggle it carefully to dislodge it, was sweating bullets not to nick anything. Again, luckily it was on the stand but still a huge P.I.T.A.

Hope you get it all back together soon.