Agree with most of the above. His neck is "upside down" more than ewe necked. All of his muscling in under his neck meaning that he holds himself hollow as a habit (exercising these muscles the most). However, in the video he CAN hold himself more properly when he is feeling his oats. With proper riding and training, you can build the topline and lose the under muscling. What you can't do, though, is ignore that his neck is pretty short.
That said, I would like him as a field hunter.