Mark G,
Unfortunately Milt is not on the selection committee.
Air sickness is still a not very well understood phenomenon whereby psychological and vestibulo/visual factors play a role.
It can get overcome and to that effect the FAA allow student pilots to fly with motionsickness suppressing medication when they are flying with their instructor (but not solo) This way they get desensitised and a lot subsequently get on fine in aviation.
That is all going to be of little help to you. I think you will have little chance of convincing the selection board to change its mind. Hard fact is that they use the selection process to find those candidates which fit within their criteria. And for every one they fail there are 10 or 25 others that do meet their standard.
By all means try to get their minds changed but don't just focus on that. Otherwise you get stuck and become a very unhappy and frustrated bunny.
The next thing to do is to have a look around and consider other options. You would not be the first to be rejected by the Dutch Airforce to subsequently have a fullfilling career in the Navy or indeed for a commercial airline.
Best of luck
FD