I was working on a little command block device to make Skeletons better in combat. It basically had skeletons switch to a sword if the player got within 5 blocks range. Everything seemed to be fine at first, until I found the Skeleton does not switch it's AI back to archer mode if it switches from sword back to bow after having been using a sword

I attatched my world file so you can try it. Just spawn a skeleton, go into survival and go into range of it. Once it switches to sword, run away and see how it keeps chasing you even after it gets a bow.