Hi there,
To have symmetrical involvement of the scapulae, the problem must be in the neck, probably between halfway down and the cervico-thoracic junction. If disc disease and spinal cord compression in this area have been definitively ruled out, my suspicion is he has a chiropractic issue in his neck. That would explain the sudden onset following a collision. Neck fixations are the most common cause of forelimb lameness, in my experience.
Acupuncture points I would use include Gall Bladder 20 and 21, as well as BL 40 and GV 14. The absence of response to NSAIDs and rest rules out Blood stasis and Qi deficiency, respectively. Sudden onset of problems involving in particular the Tai Yang channels (which serve the scapulae) usually implicates a Wind invasion. Wind invasions are non-responsive to NSAIDs and often worsen with immobility. Despite their perceived innocence. they often last for years if not addressed.
At the very least, I would seek out chiropractic or osteopathic care for his neck, use the above acupuncture points, and consider either Gui Zhi Tang (Cinnamon Twig Combination) or perhaps Du Huo Ji Sheng Tang if there is a sense of Qi, Blood, Yin or Yang deficiency. If he has ever been Damp (manifesting as allergic dermatitis, IBD, otitis externa, etc.) I'd go with Gui Zhi Tang first.
If either of the above two formulas are appropriate, the pulse will be highly toned and release with needling of GV 14 and/or BL 40. If the pulse feels slapping or slippery, I'd use Chai Ge Jie Ji Tang and would assume there is a recurrent acute peripheral nerve injury. But I bet you find the pulse is toned
Hopefully that helps!
Steve