Sighted listening unreliable?

[okiemax]

In respose to posters who claim to hear differences when using different cables, some forum members reply with the counter claim that sighted listening comparisons aren't reliable, because seeing the cables can bias the listener. The "heard a difference" claims usually are cable specific(e.g, the Kimber model X sounded different than the Monster model Y.) On the other hand, the "sighted listening isn't reliable" claims are general and seem to imply broad application. But surely, those who hold this view don't mean sighted listening always leads to the wrong conclusion. How would they know if a particular conclusion is right or wrong?