That might be a tough one to prove, Greg. First, do you know what it is supposed to do? Is it supposed to spin? Is it supposed to have a certain spray head? If you can find a brand name on the flush system then you might be able to answer those questions.
Then how do you know if it is doing whatever it is supposed to do? You could try an inspection camera I suppose.
A lot of supposition going on here. And if it were me, I simply would not care enough to investigate. If water goes in, and comes out clean, I'm done supposing.