It's hard to see anything without a stand still photo of his conformation. An American warmblood can be anything as long as there is some draft in the blood. I had a horse who was a Belgian/some sort of gaited horse/standardbred. Fancy word for him was "American warmblood", that's why other countries kind of scoff at American warmbloods. They are basically big boned mutts, while the warmbloods in other countries have specific guidelines, brands, and tests...
They have to be inspected and approve to keep their nuts, earn a brand or be bred. If they don't fit the bill, they can't be used to reproduce.
Anyways...I definitely see tb in him. I'm thinking one side was a tb, the other side was a draft cross possibly. From what I can tell in the video, he doesn't have very thick bone to be a direct draft cross. I could be wrong though, it's hard to tell.
I have heard standardbreds referred to as "american warmbloods". But its such a non-discript term and this one does not appear to be freeze branded so if a standie he is either lip tattooed or no registered with USTA.