So relieved to hear you guys took him home where he belongs. What a psycho!
I went through something very similar to your story with my first horse. I was selling my 17 years old mare, a school master who'd done hunters all her life(15'1hh, small tb frame). An absolutely fantastic horse for any beginner rider. This lady(who seemed loved at first glance), had bought the mare for her daughter(who was my age at the time, 14 yrs old and same frame as me). She vetted great, she did fantastic with her daughter, I even went and was able to visit the mare a few times during the following 6 months, everything was great.
THEN all of a sudden, I receive a phone call(and remember I was 14, she had been my first horse and this lady was a grown women), 8 months later and she was MAD. She said the mare had become a bucking bronco and was not rideable. She said she could not be caught, bridled, nothing. Told me she had turned into a complete "monster". She also threatened me that if I didn't buy the mare back from her, she would send her to the meat pen. What the heck! I refuse to believe a word she said, not to mention it was a full8 months later and no agreements had ever been brought up like that.
Anyways, I went out there, the poor girl nickered when she saw me. I caught her, tacked her up, rode her with ZERO issues. THEN I find out, this insane women, had been riding her herself! she was an overweight 250 lbs+ rider who said would only ride western. I could only imagine why the mare would have gotten mad with her. Poor animal!
Some people are honestly crazy, and so dishonest. Nothing worst than having to sell a horse, let alone find out what he/she has had to go through. Luckily you were able to bring that poor boy home. Excited to hear what you do with him.