…And the etymologies are apparently unconnected, as well. “Croupier” comes from a word for the rump of a horse, while “craps” is apparently connected to crab apples.
French Wikipedia says that craps has four croupiers: un chef de table, un premier croupier qui aide les joueurs à placer les mises, un second croupier qui paie les mises gagnantes et ramasse les mises perdantes, puis enfin le stickman 
That reminds me of the Trouble board game, with its Pop-O-Matic popup die roller. The game is basically Parchissi, but you can’t throw the die off the table. That always was a risk, and sometimes a game ender, during intense games of say, Monopoly.
Hmm, what happens if the dice on the craps table end up on the floor? Probably not good.
The roll doesn’t count. If the die is returned, it is inspected for damage, and to make sure that the serial number matches the die still on the table. If it’s not returned, or it’s been damaged, a new die is put in play.