Yeah I would be very very surprised if the water pouring in were to kill a fish/invert because the ocean is constantly moving much harsher than pouring water in your tank.
I think melosu is right on with the acclimation. Inverts are even more sensitive than fish to acclimate and just acclimating him with temp isn't enough. I personally like the shot of water every 20 min while the bag floats in the aquarium rather than the drip acclimation because the problem I have with the drip acclimation is that it doesn't keep the water temperature the same as the tank. It causes the water they are acclimating in to adjust to the temperature of the room rather than the temperature of the tank. The water from the drip acclimation isn't enough to affect the acclimation water enough.
Both method are tried and true though. Different people have different preferences. At least it was just a shrimp, not a mated pair of an exotic species of fish, though.
Also, if you've used any copper treatments or other ich treatments, these could severely affect the survival rates of inverts. Just something to keep in mind for the future.