Whoever perpetrated the crime, it is considered to be one of the most damaging scientific hoaxes of all time, because it set the development of evolutionary theory back for years while researchers labored pointlessly to integrate a fake skull into the fossil record.
From The Skeptic's Dictionary, which rather amused me considering the stance there on other matters (I put the bold bit there):
Because of the public nature of science and the universal application of its methods, and because of the fact that the majority of scientists are not crusaders for their own untested or untestable prejudices, as many pseudoscientists are, whatever errors are made by scientists are likely to be discovered by other scientists. The discovery will be enough to get science back on track. The same can't be said for the history of quacks and pseudoscientists where errors do not get detected because their claims are not tested properly. And when critics identify errors, they are ignored by true believers.
Scientists were fooled by this hoax for 40 years, until the weight of other finds finally drove some of them to take a close look at the skull itself, and find out it was a fake. One can hope things might work faster in this Internet age.