Interesting, thanks for the info.
I have one mare who pulls back, apparently when startled - although no-one can work out what she's startled by, and who unfortunately, the first two times she did it, managed to break the snap on her rope / take the fence with her. So she learned she could get free. She will pull to the point of rearing/doing a backwards roll.
I tied her using a neck rope and a body rope (bowline, nothing to tighten) - both through a normal strong nylon halter. The neck rope engaged before the body rope did. I hobbled her rear feet so she couldn't get up enough momentum to do tendon damage. At the other end was a ring cut from a tyre around a solid wooden post. I just let her think about it until she was standing quietly - qnd the following day worked on startling her with things. Buckets, tarps, foil, noisy stuff - until she stopped pulling back as a reaction. She started to get it, but I wouldn't say that the pulling instinct is entirely gone yet...
I did wonder about tying her to a highline and letting her find out about it that way, but I couldn't find two trees in the right sort of environment.