You got me with the horse example (as one who spends a lot of "relationship time" with my own horse, and I'm a fan of Temple Grandin's work. I've never thought about forgiveness in this way... but there's a lot here that makes sense. It is always a matter of rewiring--forming new neural connections. I suppose part of that new wiring could include a new perception of why the person did what they did that's causing them to seek forgiveness. We might eventually see it in such a way that it was only our interpretation that made it something to forgive.
Some things -- perhaps many things -- aren't open to reinterpretation, only a matter of whether we'll give the other person another chance.
Nice post. My horse was never abused before I got her, but I sometimes do volunteer work at a "rescue horse" shelter. And there's a place here that uses formerly abused "horses that don't trust people" as therapy for troubled teens. In learning to help the horse regain trust, the teens start to learn and think more about their own ability to trust.