Carbon dating suggests ‘world’s oldest’ Koran could be older than the Prophet Muhammad

There are a few cautions to note, and one glaring issue that, to my mind, debunks the entire argument. Let's start with the glaring issue:

Keith Small, of Oxford’s Bodleian Library, cautioned that carbon dating was done only on the Koran’s parchment and not its ink...

That sentence is reason to discredit the entire argument, because it means that it's the leather that the text is written on, and not the writng itself, that might possibly be older than Mohamed. The age of the parchment doesn't necessarily predict the age of the writing: there is no reason why the text might not have been written in 650 on 5-year-old vellum (or 695 on a 50-year-old manuscript). In fact, if the parchment were not locally produced (and, given that pre-Islamic Arabia did not have large writing centers, importing parchment is not unreasonable), it might well have taken years to reach the scribe who wrote on it. Before any argument can be made, the ink also needs to be dated. It was irresponsible for the scholars stying the manuscript to talk to the press before completing testing, and their quickness to argue that the parchment's age brings everything we know about Islam's origins into question makes me wonder if they're a little bit more interested in debunking the religion than they are in making a careful study of their evidence. (Or perhaps the reporter is quoting them out of context to make the story more sensational.)

That glaring issue aside, there's still reason to doubt the article's claims. C14 dating for the seventh century is very unreliable - to grossly oversimplify, the closer the period we're dating is to the present, the less accurate we can be. You usually only see precisions of about +/- a century, so the 77 year window the article gives strikes me as perhaps a little more precise than can be certain. I'd bet there's a low probability attached to it (not the 95% confidence you get with a wider date range). It's possible that they used a newer, more accurate calibration method to get a tighter window, or took multiple samples to narrow the range. But I wouldn't be surprised if the dates were off by half a century. Carbon dating is a great tool for narrowing down a date range (ie, is this desd body Roman or medieval?), but it's not good for precision work like this.

Even if the dates are accurate, though, they do not actually put the book before Mohamed's life: they indicate that the parchment dates to some date between 568 and 645, and a date at the late end of the range is perfectly in line with the scientific evidence. If the parchment came from 645, that puts it 5 years before the probable compilation of the Quran. Given the fact that the parchment may well have been a few years old at the time of writing, that would make this a very, amazingly early copy of the text, as close as we could hope to get to a first edition. But that doesn't disprove anything - if the accepted narrative is correct, there were first editions made in the middle of the seventh century, when this book was probably written. We just never expected to be able to find one of them still intact.

There are other technical questions that could be asked: what C14 methods did they use? How were the dates calibrated? Small variations in procedure and methods can skew results by decades or more, so all else aside, this test is not necessarily the final word.

In sum: we need to wait until we have more data to know for sure that the dating of the written text - and not just the parchment it was written on - actually falls within the range given in the article. Even if it does, given the error associated with using C14 to date recent artifacts, that date range is not incompatible with our current understanding of the compilation of the Quran. I'm not at all convinced by this.