Turning the foot out and lifting the toe could well be simple compensatory strategies for him not wanting to put this heal to the floor in dorsi-flexion i.e. a tight calf area and or a stuff ankle joint. You could go the the local chemist and buy some heal wedges for his shoes/trainers (if he wears them). I would think at least 5mm so you might buy a few and stack them up under the innersole. Slip them into his trainers to see if that allows him to land more evenly on the heels. It that works in the short term you can gradually reduce the height of the lifts as his muscle accommodates more to the stretch.