In particular, his comment asserting:
The large majority of the evidence suggests that the Shroud of Turin predates the medieval era. The 1988 carbon dating of the Shroud is an exception that's often cited. However, there are a lot of problems with that carbon testing. Dan Porter has gathered together some of the relevant evidence here.is misleading at best and more generally speaking, out and out false.
The statement is misleading because "evidence" isn't like people. It's not like there are five personified evidences, named James, Bob, and Sparky, and only Sparky says X, while James and Bob say Y.
Moreover, even within categories of evidence, how we pick our categories ends up determining the majority. There are three main categories of evidence: Scriptural, historical inquiry, and scientific examination.
On Scriptural inquiry, there is virtually nothing to support the shroud. The Scriptures specifically relate that Jesus' body was wrapped in multiple linen sheets (not a single shroud), that his body was covered with about 75 pounds (American weight) of spices, and that his head was separately wrapped. Moreover, the long-haired person depicted in the shroud does not correspond well with Paul's comment about nature teaching that is a shame for men to have long hair, though it accords well with medieval European iconography. Moreover, there is absolutely nothing in Scripture suggesting that Jesus ever left a miraculous image of himself on anything. Furthermore, the burial wrappings of Jesus are specifically described in Scripture, and there is no mention of a shroud. At best, one could hope to find a way to work a shroud into and around the Scriptural evidence, but the Scriptural evidence is uniformly against the Shroud's authenticity.
Historical evidence. The currently prevalent view is that the shroud we see today is the same shroud described for the first time in the 14th century. If this is the case, then the farthest back that the shroud can be documented is the fourteenth century. It's difficult to be sure whether this shroud is the same as that one, but let's concede that for the sake of argument. The absence of any prior history of the shroud (especially given the iconomania of the preceding centuries) is a bit like the dog that didn't bark. Be that as it may, at most the historical evidence can establish a 14th century date for the shroud.
Scientific evidence. The most reliable dating method that has been applied to the shroud is C-14 dating. Like every scientific test, there limits on that reliability. Nevertheless, three tests were performed, and the conclusion was that the material of the shroud dates to the 13th or 14th century with about 95% certainty.
People have proposed other dating techniques, ranging from the absurd to the trivial.
An example of an absurd dating technique is the technique of comparing the shroud to medieval iconography in terms of realism and/or technique. This is an absurd dating technique because it merely demonstrates that the shroud represents a unique artifact, regardless of its date. In other words, it's not as though the shroud represents 1st century Palestinian techniques, but not 14th century European techniques.
An example of a trivial dating technique is the "vanillin dating" approach. There are a number of obvious problems with this technique, the chief one of which is that it lacks any substantial body of scientific research that can authenticate it. A secondary problem with this technique is that the process involved is temperature dependent, and it is already known that the shroud was exposed to fire. A third problem is, if you actually bother to go and read the place where the "study" was offered up, the scientist who provided it himself acknowledged its shortcomings.
Looking at the "scientific" evidence in the light most favorable to those who imagine that the shroud is more ancient than History, Scripture, and Science all suggest, the most that can be said is that there is some kind of remote possibility that the sampled pieces of linen may have come from a part of shroud that was repaired by someone who deliberately attempted to deceive the viewer of the shroud by hiding the repair.
So, the best case scenario for shroud advocates is that part of the shroud is a hoax.
In point of fact, while there are mountains of evidence so-called, there is no reliable evidence that suggests that the shroud is any older than 13th century. The shroud may still be interesting, however, as the earliest known photographic negative.
The reason Mr. Engwer's comment is misleading at best is that dating techniques are not all equal. That said, I still love and appreciate Mr. Engwer, and I want that to be totally clear. I willingly accept his assertion that he honestly believes that he is simply convinced by what he thinks is the evidence.