What do you think about this horse?

I don't know much about that specific breed but there is something about his hind end that looks off to me... I think it might just be the camera angle or even his lack of muscles but it is still something that I would want another picture at a different angle for just in case. Other than that the people sound like they know what they are talking about so you just need to use your experience and think of information that you feel is important for you to know about your possible new horse. Good luck with him!