He's a lot more like the second one. His real bolts are more extreme, though—with all the back-hollowing, head-raising running off but not slowing down enough to buck or mess around. (Like I said, hasn't happened for a while.) Usually I know it's not a real bolt or a proper scare if he has time/thought to put his head down and buck (when he does, it looks very much like that video, and is under control again about as quickly.)
My Arab/Percheron gelding was more like the first horse. Not quite as explosive, but close. He did strike an instructor once that was standing at his shoulder, and the first time I lunged him was very similar to the clip in the first video, except Baby reared up and came straight at me.
My Appy/TB mare was more like the second clip, so maybe this bolting/bucking stuff is an Appaloosa trait, not an Arabian trait!!! (just kidding)
My grade QH was more like this horse: https://www.youtube.com/watch?v=TBUSt8hPwio
So, if your horse is more like the second horse, I would think it is more of an attitude problem, as you said not a "real" spook. There may be pain involved or harsh early training that makes a horse fight when stressed.
The first video, is what I call "baby stuff" from a horse that just doesn't have enough confidence and gets flustered easily. However, it is the most dangerous, cause the horse is not listening to the rider at all.
The one above, in the Olympics, I think is an example of too much stress and this is the only way he can tell the rider that it is just too much for him to handle. That's what my grade QH would do.
I sure wish you had a video of what your horse does Pho, because it would really help me decide if it is something i can work with. If I was 20yrs younger, it wouldn't matter, but I don't recover as quickly as I used too, and the ground is a lot harder since my pasture is on the side of a mountain and I don't have a sand arena, or really any real arena at all.