I looked for Olor's post, but couldn't see it so I don't know what tactics (if any) he was employing. However, when I went to get my own quadav stew at level 40, I followed the currently acknowledged facts about steal rate that were on allakhazam at the time, which were:
Steal from behind. Steal while the enemy is casting/TPing/otherwise distracted by another player.
as memory serves, I had 1 fail from using sneak then trying to steal whist not engaged, then 2nd attempt, I picked a zicon quadav, didn't engage, but locked on from a distance. Ran up to it without sneak to agro it, it started to nuke me, so I spun around it while it was casting (now you see why I locked on without engaging) and stole the stew from behind. No steal+ gear (I was 0/3 on JEJ)