Hi Phyk,
sounds like bad news. Unfortunately I do not think the quacks at the DFR are lazy and just because they have not come across your condition before does not mean that they are tossing it into the too hard basket. There are a number of ways to look at this and all end up being that the ADF do not have to take a chance on you. It basically boils down to why spend numerous dollars (read a large amount here) with someone that has a condition that may affect (disregard CASA they allow people with heart conditions etc to fly) them in the air or render them unfit in the future. How does your condition respond to high G and repeated high G manoeuvres? It is very similar to the entry standards, for eye sight, whereby you need to meet the initial criteria on entry but once in, one day later, be as blind as a bat.
Your brain spec lad may say it is all fine but what is his aero background?
By all means go through the appeal process but don't be surprised that even with the backing of your specialist the ADF still says no.