Without getting into a lot of detail, no one now seriously claims C-14 says anything accurate about anything 100,000 years old. The far end of the spectrum that I've read for most optimistic proponents is 50,000 years (though it used to be cited for greater ages). At that, C-14 has been recalibrated in Europe and the American southwest in the past decade to more closely match dendrochronology, because C-14 dates beyond about 2,000 years (sorry, that's even shorter than the length you suggested) have been found to be inconsistent with the determinations of dendrochronology (the assumptions didn't work). If the assumptions about dendrochronology, and the subjectivism and statistical generalizations do work (I greatly doubt it), that would be helpful out to about 10,000 years, a far cry from 50,000, and no hope at all for anything "older." The parenthetic comments are strictly mine, for background on the other bits, see the pages (links) I previously referenced regarding dating techniques, which are on university sites, not creationist sites, that I had chosen at random from a web search, not selected for particular emphasis. Creationists don't necessarily question constancy of decay rates, though some would in some cases since our opportunity for a window of testing belies the presumption of uniformity of decay over vast periods of time, but the more likely question regards the assumption of uniformity of distribution of C-14 throughout earth history.

Generally, regarding radiometric dating techniques, one doesn't have a range of dates from redundancy, testing a number of samples, one has a range (a vast range) of dates from multiple tests of each sample.

Essay says Neandertal is nothing like Homo Sapiens. That's quite an overstatement. Neandertal is classified as Homo Sapiens. Poor old Neandertal has taken a lot flack over the years though. There seems to be an inference in essay's post that Neandertal and Homo Sapiens Sapiens (Modern Man) did not coexist, but that is certainly not the current belief (of evolutionists) either. To the best of my knowledge the currently accepted perspective by virtually all anthropologists and paleontologists recognizes the lengthy contemporaneous coexistence of Neandertal and Modern Man, side by side and sometimes in very close proximity and possibly competing. The questions tend to be about whether they intermingled and interbred, or could interbreed, and how much they interacted, not whether they coexisted. Bones have been unearthed in French caves that appear to be crossbreeds of Neandertal and Modern Man, which is a controversial topic among anthropologists. In and of itself, the remains of Neandertal or Modern Man inherently tell us nothing about sequence or chronology or relative age. The picture gets marvelously complicated from an evolutionary perspective when homo erectus and homo habilus (a handy catch-all category) remains are added in, and there are instances of bones (and footprints) being categorized as HH or HE solely on the basis of supposed date, despite being indistinguishable from MM. It's all a jolly game. I've recommended it before, but try the book "Bones of Contention" by Lubenow, and don't take his word for anything, since he apparently is tainted and untrustworthy as one who believes in creation, but look up the references and cross check the data he compiled. It's all from standard sources widely avaiable.

The current idea in evolutionary dating schemes, as far as I know it, is that Neandertal died out about (after) 30,000 years ago -- that is based on what are deemed the "most recent" Neandertal bones being dated to about 30,000 YA; and Home Erectus supposedly died out about 53,000 to 27,000 years ago. I love those date ranges (see "Homo Erectus Survival" in Archaeology Magazine, March-April 1997). That becomes even more problematic when features of modern Australian aborigines are compared to HE, and it starts to sound like the old evolutionary racism of the 19th century all over again, and nobody wants to go there. Then too, there are skeletons turning up with "neandertal features" being dated to about 24,000 years ago in France (see ARTICLE. It's all a marvelous hodge podge and not nearly as simple and definitive as most people who swallow the dating methodologies would like to think. I know less than 30,000 years (or less than 24,000, do I hear 20,000?) is not the 10,000 years that essay asked for from a non-evolutionary source, but then Neandertal has been all over the family tree and up and down and all around in the dating game in the past century.

Personally, when thinking of Neandertal, I suspect the Hebrews spelled his distinction Nephilim, but that's just my own odd perspective.