Horse has not done 360, that would be back at starting point, full circle.
Horse has done 180, meaning horse is opposite of what was.
I disagree with the whole concept of "horse equating trailer with work, give horse time to unwind, don't just load and go".
We load, ship and work horses all the time. People bring their horses to barn to work in arena and be fine tuned. And are loaded and hauled out when done.
With young horses that have not been trailered before, it may take longer. Maybe 30 minutes at most. With a spoiled horse? 3 hours as horse had been babied and petted to where it didn't think it had to do anything but what it wanted to do.
Does that same horse now load nicely? Yes. We got it back to barn, it was worked daily, not babied period, and after couple of months, show season going and she wasn't on show string, so no hurry, we hooked trailer up, pulled it out, got mare out and taught her to load nicely in maybe 30 minutes. And that was extent of it. Loads like a champ now.
I would imagine that this horse may have been spoiled over the winter months, and attitudes and behaviors that would have been view by some of us as challenging, have either been missed or ignored.
Horse, of course may have just been left out to eat off of round bales and not messed with much, you didn't say what your situation is?
But horse has your number, and mom's. Knows you all aren't the boss in other words. Horse is fine with whatever you want it to do IF it suits the horse's program that minute. If horse doesn't want to do something, as in this case? You will see exactly what you are seeing.
And horse will carry this over to everything else too, if you don't learn better horse handling skills. The fact that it is acting up that far from the trailer, 15 feet? Tells me horse isn't scared, horse is telling you it's boss.
And the whole concept of "oh, horse equates trailer with work" and "let horse unwind" is malarkey.
What's next in the mode of thinking? Standing at window to see if horse is equating being caught means work? Oh wait, that is being done elsewhere....maybe seeing if horse is giving off vibes that it would fancy a quick trip around the yard?
Horse knows you aren't going to be serious about it loading, and is showing you who is boss. And it is not you.
The things I would do, or Bob or Cherie for that matter, I hesitate to suggest, because without someone there that knows how to handle horses, it would probably be a disaster.
If this were my horse? And it KNEW how to load? I'd either drop loop over haunches to rest above hocks and tell horse to come up, tighten loop to make my point and load it.
Or if trailer configuration permitted? Run lunge line from halter through front window and back on outside of trailer to me, put steady pressure on it, and take a lash whip to hind end.
And no, you don't have to "beat horse like a cheap Sears rug", merely showing it to one is enough, and with others, a good pop works wonders.
Horses are very quick to figure out who they can buffalo.
Horses make me a better person.