I do not know everything about this horse, but what I can see now with my minute experience (let's be honest, it is still 0.001 out of hundred) he had not had suitable rider. Wrong horse for wrong rider. He IS A HANDFUL at present. So maybe somebody just get really frustrated and gave up on him. Could happen, especially with people who ave a lot of money.
But it could be also different - we were told that he has medical issues - that fact that nobody had spotted anything so far does not mean that he has not - maybe when he will start jumping more serious heights he will show the problems.
So we are just keeping our minds open and hope for the best - just re-training. But even by the worst scenario (can not take serious job due to medical issues) he will be completely suitable as somebody's sweetest hobby horse after re-training.I'm not frightened of him anymore - he is basically as sweet as Shella is - and it means very, very sweet and cuddly. The worst part of him is mounting - you instantly must grab reins as he pulls like mad - go, GO, GOOOO! If you calm him down, he is very nice walker, a bit harder on trot and goes wild when canter. Today Peter got a nice cantering out of him just for fewminutes, but it was already an archievement.
He does not back or rear with rider, not at all, he just seems really confused and probably had too weak rider who was not able to control him.So now he must learn to trust rider and calm down. If that will be all his problem, then we are winners.
Peter just walks and stops, walks and stops, and only then, when Guido is relaxed enough, lets him trot a bit, and if he gets excited, back to walk and stop... He does it very well, and he relaxes after regular patting and telling how good he is. He listens, relaxes and enjoys more every next day.