system
...result is displayed on the screen within 20 seconds of hitting submit.
I gotta say some of my exam results felt like they took much more than 20 seconds!!
Skillz
I'm afraid it seems unlikely there was such an error for your exam - to be out by a factor of 30-40% like you suspect is quite a massive technical problem! Before spending the money getting the result reviewed, how about tracking down some of the others in the same examination session and seeing if they had any problems.
From personal experience, Aero confounded the hell out of me! I was also sitting on 85-95% for my other exams, and was scoring 95-98% in practise exams from CASA, AFT, etc. First attempt: 68% Probably the worst feeling you can get!
Went back to the books for the next week and resat Aero to get 65% the next time - more study was actually making me worse!
After 2 fails in a short time period, I had to have a gap of a month or 6 weeks (I think) before being able to resit it. Didn't even touch the books again in that time. Cruised through with 88% on the third sit.
You'll manage in the end, but I gotta say 45% must have been a rude shock! All I can say is good luck!