The villager must be a master farmer. The others see something in the lagoon, but don't hunt for it. I've been fairly lucky; most cases my farmer has caught the fish after only one or two attampts. If you've got more than one master farmer they can all go hunting, and can each catch a fish. At one stage I had three proud fishermen in a line walking back with their catch. However, the one that gets first to the food bin is the only one that counts. The others will drop their catches when he gets there and start celebrating.