Eh - photoelectric effect, fluorescence, phosphorescence, backscatter - it's all the same to these guys. Since Henry Blair left, it's not exactly like CDEx has a stable of Nobel Prize candidates or anything.
I mean given their track records and evident limitations, the fact that they are even able to hook up a COTS fluorimeter and calibrate it is about what we should expect from them at best.
Don't start getting into the Dirac equation or anything complicated with them.