Currently when you press z to abort a controlled teleport, it teleports you randomly. You almost never want this to happen. With teleportitis it becomes quite obnoxious since the teleportation prompt can come up at any time. If you aren't paying close attention and are in the middle of repeatedly casting spells or using wands, you can easily get an unintentional random teleport.

Aborting targeting should teleport the character in place instead. If you want a random teleport for some reason you could still easily get one by targeting a wall.