I think you've gotten some great advice. I don't see lame either. I think AC hit the nail on the head about him looking like a speed horse that's been in a tie down for awhile. He is tense and bracing. I don't see a horse anywhere near ready to learn reining maneuvers.
Take it slow and back to the basics. Even if he's had previous riding, treat him like a colt that needs a foundation. He needs to learn to give to the bit & relax. Spend a lot of time just walking and doing that and putting a good relaxed neck rein on him before moving on to a faster gait or advanced maneuvers. Once he's light & supple at a walk, then move on to jog.
Life is like a camera. Focus on what's important, Capture the good times, Develop from the negatives and if things don't work out, Take another shot.