Leoben wasn't lying. The radiation affected Doral the same way at the end of the miniseries when he was left for dead on the station.
They didn't mention exactly what it was, just that "something" had an effect on the Cylons silica relays in their brain.
Actually, I think you're right.
On the plus side, I just invented my own Cylon detector. All I need is a small sample of nerve tissue and a spectrometer.