How in the hell could anyone have even known where Locke and the rest of his group were to fire missiles at them. If the walky-talky was a tracking device for the first explosion called in by Zoe, it is smashed and is in a totally different location. You have to have some type of eyes on target to call in coordinates or a beacon for this type of strike. I feel this is just absolutely ridiculous that they could have known their location at that time. They were on a bloody different island. The MIB would have sensed if someone had been tracking them and would have annihilated them immediately. He already stated "it is on!" IMO this was down right stupid without showing the technology they were using behind the scenes at the Widmore camp.