Unlike the civil courts you don't get an order for costs just because you have won. Costs are awarded only when the conduct of the appeals is unreasonable or they stood no reasonable prospect of success. Failing to notice that your evidence is inconsistent with your own case is fairly basic and frankly surprising, as is producing no evidence at all in support of a ground of appeal. The Inspector's assessment of the evidence on oath he heard is also fairly damning of those who gave it and the party who lead that evidence.
All very odd given that the appellant appears to be a solicitor!