I've been flipping through Earnest Hooton's Up From the Ape (1946 edition). It's a remarkable book for many reasons. I'm almost transfixed by his discussion of Piltdown. Only a few years from its final exposure, the cracks had long been showing. Hooton showed scholastical ingenuity as he propped it up -- a full eleven pages of discussion with the heading, "Dame Eoanthropus: The First Female Intellectual".
To someone reading today, familiar with the details of the hoax, it's just striking how Hooton covers all the problematic areas and explains them away. A sample (p. 312-313):
Now the temporo-mandibular joint in Eoanthropus is a deeply excavated glenoid cavity with a high articular eminence before it, as in modern man. Condyles of the human shape are required to fit into the glenoid fossae. Unfortunately, the condyle is missing from the half of the mandible recovered. So it cannot be proved that the jaw belongs with the skull by fitting it to the temporo-mandibular joint. This absence of the condyle has afforded yet another opportunity for the separatists to affirm the lack of kinship between mandible and brain-case. They allege that the lower jaw, being almost wholly simian in shape, should be equipped with an apelike condyle that would not fit the modern type of glenoid fossa in the temporal bone. A further difficulty lies in the fact that a long projecting canine tooth, evidently a lower canine, has been recovered, and we should expect jaws with protruding apelike canines to be fitted to the shallow articular plateaus of the anthropoid rather than to the deeply excavated glenoid fossae of modern man. In order to fit the simian jaw to the human socket, we must model upon the mandible a humanly shaped condyle that is incongruous with the rest of the bone. This little difficulty need not, however, embarrass us. If nature puts conjoined human and anthropoid parts into the same organism, some compromise has to be made at the junctures.
The blind spot, of course, is the failure to guess at malice as a reason for the strange features. Sure, there are anatomical elements of Hooton's discussion that no longer hold water, but there's no avoiding the main issue: Nothing is more natural to the academic than trying to explain the inexplicable.
It is a certain failing of logic. Sherlock Holmes' dictum: "After eliminating the impossible, whatever remains, no matter how improbable, is the truth" works perfectly well. But it is so easy to talk oneself into the possibility of the impossible.