My recommendations for pullers or to simply alleviate the worry is to do the loop around with an extra long leadrope. The more times you loop the harder they need to pull to get totally free, so it works a lot like the blocker tie ring, which also recommends a long lead. And that is my second suggestion. Sometimes you cannot loop around. Such as tying to a trailer or some kind of tie ring.. That is when a blocker tie ring, or one that works similarly is great.. I've seen one that is like a huge snap that works well on tie rings(trailers etc). You snap it to the existing tie ring and your lead threads thru the loop below it.
Cash did a couple of hard pullbacks the other day in a rope halter tied to a ring, bout never got that untied.. Rope halters are designed to put enough pressure to discourage pulling back. However when a horse loses his mind temporarily they don't always feel it right away. I let him figure it out for himself. If he had gone into a full blown fit I would have undone him.. Well, I'd a tried. LOL He will be looped from now on. It's just safer with kids around too.