It is hard to tell if the new livestock caused the cloud.
My first cloudy tank occured years ago with a 10g and about a week ofter I added some flake food to start the cycle. What had happened is that bacteria build up to process the food and they died off from lack of food. It was the dead bactera which caused the cloud. If you cycled with a dead shrimp then I highly suspect the shrimp, not the hermits are the cause. As you stated, Uncured live rock could also cause the same problem. The way I of got rid of that and other clouds was to run filters with either lotsa carbon or "water Polisher" filters. Always took 2-3 days to clear up. To prevent a return you need a constant bioload so bacteria die offs do not happen. If the cloud is small or just some stirred up sand, it will clear up in a couple of days. Otherwise you will have to filter it out.
The prevention is to provide a constant bioload to build up the bacteria to a constant level.
As always I recommend macro algae or marine plants to balance and stabilize your system.