Perhaps one should distinguish epistemic peers and cognitive peers. In a scientific domain, a cognitive peer is another scientist who is equally expert in the same domain. An epistemic peer would be someone equally capable of evaluating a theoretical claim without necessarily being an expert in that particular domain. Your example of the scientists who work on Homo floresiensis seems to me to be of this type, as each may have a different background, and so not be cognitive peers, but be equally capable of evaluating certain transdisciplinary projects, and thus epistemic peers.
My worry about the way that the notion of cognitive bias is sometimes bandied about is that it is in danger of being a way of accomodating subjectivity inside a scientistic framework as mere noise, bias, and error. Bias is harmful in science, as in life. But sometimes bias is essential as without it certain experiments would never have been performed. I am thinking of Eddington’s famous observation during an eclipse to confirm Einstein’s General Relativity. Eddington was “biased” in favour of the theory before testing it, and on certain accounts even slightly fudged the results of the observation. Feyerabend proposes that in such cases we can drop vthe negative epithet of “bias”, and rationally reconstruct what is happening as “tenacity”, which he holds is a very useful epistemic strategy, precisely for the reasons you invoke in the consideration of “confirmation bias”. Obviously, people can be in denial, or just pig-headed, and this is bad. However, every theory has disconfirming instances, and we often simply don’t have the time or the means to explain them away. Paying attention only to confirming instances may look bad in an artificially contrived laboratory situation, but may inspire admiration when found in a “visionary” mind tenaciously pursuing its intuitions against prevailing opposition such as Galileo’s or Einstein’s. I apologise for using only “epistemic” examples to hammer the point home, but one could also cite the early Christians, or explorers like Columbus. The whole Christian notion of “felix culpa” is for me a critique of taking findings such as those about cognitive bias too absolutely.