I tried to add this above.. but it was too late.
In the trotting photos at liberty this horse naturally travels heavy on the front end. He has more contact with the ground with his front feet than his rear feet. In the bottom photo where he has his head up, and his back hollow, his hind feet are actually off the ground. Even though he appears up hill in this photo, he is stiff and he is traveling weight front. In the top and second photo it is better.. and in all three he has a hollow back.
His hind legs actually have a nicer and longer reach than his front leg because he is better constructed behind (although a bit straight through the hock).
Again. A nice horse but with faults that are shown really well in the photos.
Thank you to the OP for posting this thread. It is great to illustrate what I say and these photos allow for that very nicely!