First of all, If you are running a BH mission on another player and while doing so someone else kills you by either PvP overt or they are a BH and taking your mission, you will then have a Perma TEF on the person you had the mission on. It's funky but the first time this happened to me I went on for several hours killing this guy and him killing me until one of us logged.
Additionally I had the same thing happen with a differant situation, this time it was strictly in PvP on my Spy, I'm not sure at what point the TEF occured but needless to say I killed the same guy over and over for over an hour until he logged. I think after the 50th time he died inside the cloner he chose to clone some where else, lol.
Also I would like to add that the current way to TEF people is still working.... to an extent. I'm not sure if it's just me but I've noticed that most times when I die and the person who killed me has a DOT of some type on them, my clone window will stall until the DOT wears off and then my clone window pops up. It seems to me like the Dev's are trying to work around people being able to TEF other players right out of the cloner.