Problem Alert

So, I'm suppose to take care of a Quaterhorse named Rally but his owner said that he is having bad behavior problems. She could have been hinting that I taught him those problems. And she doesn't want me to ride him. I've only ridden him once... :-( I don't think he has a problem. Maybe she doesn't like me or maybe she is just jealous that she can't ride him. Oh yea I forgot to mention. She can't ride him because she has a hip problem. So... What should I do???