Unfortunately a tick is more than enough time to ensure that you can get away without too much worry of being found again. In certain circumstances you could get far enough away to heal up out in the open enough before they find you again and you're fine. Or they find you quickly (in specific circumstances) where you can easily just recall if you're not cursed, or even teleport elsewhere where by that point you'll survive pretty much anything. I'm okay with people being able to outrun me if I manage to get them to that point, but to have a kill taken away because you were left ensnared because certain circumstances weren't met yet seems to be a bit annoying.
Spirit Bind would probably help some, though in your case as a Shaman and your regen for both HP and Mana are very important, it's hard to say if it will always be useful or not. You could test it out here and there though to see how useful it really is. And those shopkeepers are definitely nice to take down considering, and if you have the strength and weight to carry it, grab a corpse on the run and drop it when you need it most. Yeah it will only be a few hours before it rots, but it gives you enough time to capitalize on it most. Get more of those things you use though on top of all that to fully capitalize on it. The fact that you've had him run as an Undead Monk is humorous to me considering most Shamans die so easily to an Undead Monk even if you don't have saves. Nebu is definitely the powerhouse though of all of them considering.