I don't happen to believe that dogs that falsely alert can be described as defective, I think that is somewhat unfair. No one here is dissing the dogs (as you seem to be doing) merely stating that unconscious handler bias is a recognised and proven phenomenon in sniffer dog searches.
You asked me how I accounted for the "woeful" performance of a woofer on a job in Scandawegia did you not? I gave one possible reason.
OK so if we consider this as an instrument loop it has two components man and dog and a loop "communication" medium. If the loop is consistently incorrect there are several potential causes. The signal from the dog to the man is incorrect; the signal from the man to the dog is incorrect; the dog is defective; the man is defective; the wiring[communication medium] is defective.
All are possible, I fail to understand why you are labouring just one particular reason out of several, then attributing to me things I did not say. What precisely is
your point about operator bias other than it is a recognised phenomenon?.
So if a doggy is cued by his handler and finds a piece of evidence that is upheld by further examination and tests is that piece of evidence nullified by the dog being subjected to operator bias?