A fighter or dende can teleport directly to you if they add you to their friends list. On DBO, friend list is not mutal. You can add someone as your friend and they don't know about it.
If it wasn't a fighter or a dende, then it could have been yardrat memory item (which you can save locations to and teleport using that item) or NPC teleport.
Now I get it! Thanks for your help!