This isn't new information at all. It's been discussed in the thread already. Also, step 3 is no longer correct with the changes to MD, you don't have to autoshot.
Well i took a 3 month break from the game and when i went back into ZG for the first time a few weeks ago, my first couple of Thekal pulls went bad as well. I can't pinpoint exactly what was going wrong, but i made a couple of simple changes to what i was doing and i haven't had a single bad pull since. All i do is:
1) Leave pet under the back part of the first arch heading into the area. Make sure he's set to passive.
2) MD pet and run into maximum range of Thekal.
3) Hit your auto-attack and let it fire twice.
4) By the second auto-shot Thekal and his gang should be almost on top of you (if you don't have Hawk Eye). Feign Death.