you mentioned that the horse seemed sluggish it could be that they drugged the horse to make her calmer. that happened to me years ago my boss bought me a gelding (my boss raised horses and i kneed one i could handle) any how the horse acted great untill we got him home, he wasnt wild just hard to control, and the age being off even if it was her uncles horse she should have known the age of the horse, most people would ask, then to show papers with a diffrent age not a good sign.