|The numbers 'mitre' be wishful thinking.|
Pardon my exasperation as I usually do not comment on such things here -- especially in a vulgar manner as this -- but:
no.. no.. No.. NO.. NO! This is not how you average dating tests!
All three tests are completely inconsistent with one another, and due to this large swath of inconsistency should be thrown out (and would be thrown out by your average statistician). Think about it: The collective margins of error min-max to 700 BC to 800 AD -- Or about 1500 years of uncertainty.
Averaging them the way the author did falls victim to the so-called Texas Sharpshooter Fallacy.
In essence, it's hole-y argument, not a holy one. Wholly. :-)
If you want to know more about some more serious Shroud of Turin research, I suggest that you go read the work of Antonio Lombatti (blog, turin search). His commentary can be a bit biting at times, but he's quite the expert on it.
UPDATE: Archbishop Cesare Nosiglia (The Archbishop of Turin and custodian of the Shroud) has come out against these test results, saying that the provenance of the cloth that Fanti and Gaeta tested is squiffy and probably did not come from the Shroud at all:
"Non essendoci nessun grado di sicurezza sull'appartenenza dei materiali sui quali sarebbero stati eseguiti detti esperimenti al lenzuolo sindonico - si legge in una nota di monsignor Nosiglia - la proprietà e la custodia dichiarano di non poter riconoscere alcun serio valore ai risultati di tali pretesi esperimenti." - [Ansa.it]Roughly (as my Italian is a bit rusty):
"Since there is no degree of certainty as to whether the materials upon which these experiments were carried out belonged to the Shroud -- says a statement from [Archbishop] Nosiglia -- the custodian declares they cannot recognize any serious value from these alleged experiments."
DISCLAIMER: Don't think me wrong. I think that relics are awesome (for example, I'd honestly love to grow a cutting of the Glastonbury Thorn, regardless of its origins), but the Shroud, like so many other relics, is a fake. It doesn't fit how Jews were buried in the 1st century (both the size of the cloth, how it was folded, and the weave of the fabric, itself). Sadly, when it comes to bogus relics they say that if one were to gather up all of the pieces of The True Cross that have circulated throughout the ages, that one could easily build Noah's Ark with enough left over for a couple of deck chairs.