MKAC, that is an awesome, beautiful story. A great way to deal with the horse's very real fears and trust issues, and a great, compassionate way to deal with your friend. You sound like a good, good friend.
I wish my friend could understand it in that light too. My distance is some respects is just me/my personality, but it is also a wariness/suspicion/skepticism that is part of the pattern created because of my emotionally unsafe childhood ...... the desire for connection conflicts with the desire for safety remembering that connection has at times been unsafe.
Intellectually, I know that this friend, and others, are safe .... and yet the protective mechanism is there and is a part of me, is me.