Are we talking Stylus or Cantilever? I have a hard time believing as you were preparing the table for transportation one of you looked over at the arm and cart, and noticed the stylus missing. Its difficult to glance at a cartridge and see the stylus missing from the cantilever. Again assuming the gentleman removed the arm and set it on the shelf and at that moment you noticed the stylus missing. How did he set a tone arm on a shelf with the cartridge still mounted to it? Most tone arms dont sit up right easily, with out being mounted.
Now if you transported the table to your home set everything back up and lowered the arm on a record to listen and the arm, cart and cantilever skated across the record, then how do you know what happened? Transporting a turntable arm and cart is risky business. I would not of removed the arm and cart from the table. I would of taped it in place. Thats simply unnecessary work. Transporting only an arm with a cartridge attached is dangerous. How do you orientate the arm? The arm mounted to the turntable is a much better situation for driving home.
Anyways I hate to be doubtful, but if you were moving and dismantling the table, chances are one of you made a mistake and failed to realize it. If the table was sitting at home, unplayed, with no children, wife or maid around, you come home and the cantilever or stylus are lying right below where the arm is resting... That sounds like it just fell off. The fact that you were in fact removing the arm from the table with the cartridge still mounted, leaves me to believe a mistake occurred. If I have to remove a tonearm, I remove the cartridge first. Tonearms are much harder to break than cartridges, but they also have a bunch of moving parts, that makes them buggers to hold, mount and remove. Always take extra steps to protect the cartridge.
Rudy