Ghost shrimp are really sensitive to changing water conditions, including temperature, so that might be your culprit. He might have died before he got caught on the tube and then been pulled up? I watched mine carefully around my intake and they've swam all around it and not been pulled in, I have it at about 1/2 power.
Everything I've read about ghost shrimp suggests that they really do best in a fully established/cycled tank. Since you said that your tank is only five days old, it could be that the water stats just weren't stable enough for them yet.