If the evaluator did not mention form with your lower body, it might be worth it to fiddle around a little bit with your binding angles. Also, how strong are your ankles? That *may* play a small roll in the pain and strengthening might help alleviate the discomfort.
I am by no means an olympic athlete, but I am pretty active. In the summer, I bike, run, and longboard. Winter is pretty much 100% snowboard, roughly 3 hours a day, and all weekend.
One thing I did forget, this past summer I did mildly sprain my right foot (lead foot). However, it was near the start and never noticed any pain with my other activities. So it could be still weak in certain areas, and now that I have gotten better I am stressing that area.
I have scaled my angles back, but I only spent one day at +15/-15. Since it was already sore, I doubt I would have seen an instant recovery. Going to keep them this way for a few days and see how it goes.
The pain isn't terrible, but it has got a worse. This weekend was family day (Canadian long weekend), so I put a solid 4 days of riding in.