A temper tantrum of that magnitude out of her is really surprising, unless that is why she was let go from the dude ranch. Any clues of this before? Did the trainer there see it?
Are you sure her saddle fits well and is correctly positioned?
I knew I needed to get back on but not til I knew what was wrong. I went and got the owner. She was shocked. She didn't want me to ge back on today. She said it was too dangerous with rain and mud and she couldn't risk getting on herself because she just had knee surgery. Tomorrow the trainer going to check her out.
She told me to longe her. She said she didn't care how muddy the round pen was. I ran the crap out of her. Just did it free style. After a few minutes I realized what I was doing and felt really bad about myself and stopped. I wasn't longing her to ride again. I was punishing her and she probably had no idea why. She was fiesty though. Throwing that butt up. Anyway I just put her back in the pasture.