Accidental frag and a pistol wielding thief

A couple of months ago I brought home a 4 head branching hammer. All was well until a tumbling rock mishap provided me a clean cut single head frag from the original 4. I was sure the single was not gonna make it but placed it in the sand and it seemed to be none the worse for wear after a couple of days. Several days later I noticed that it had been dislodged and the current was gently rolling it on the sandbed. Time was short as I was headed out the door so I quickly tucked it back in the sand and left. Upon returning home I discovered the lil guy was mia...no where to be found looking from any angle. I gave in that it had been swept under the rock work and was a gonner.....then, two weeks later it suddenly appears lightly rolling near the rock looking great. I again plant him in the sand and vow to get some glue to mount him to a plug or on a rock but that will have to wait until the next day. Next day...mia again for a few days then reappears. The area where he keeps reappearing from is right next to my pistol shrimp's home. Come to find that the pistol is taking lil frag in his home and then later pushing him out to the edge. Caught him take the frag and place it next to the opening of his cave and treat it as if it was a watchman goby (don't currently have one) then drag it back in. Happy to say that the lil guy is now safe from the thief and still doing great. Strange things go on in our tanks.