The probable reason he dismissed your theory out of hand is that he has access to all of the current research on the Shroud. He has seen and heard everything that has been proposed... and some DO need to be dismissed out of hand because they do not match the known facts. Faith has nothing to do with Barrie's fascination with the Shroud.
Barrie publishes articles both pro and con about the Shroud... when they are scientifically based. Wild conjecture and theories not based in history or science are rejected.
In about 10 minutes, I am leaving to see and talk to Barrie. I know him and he is devout in his Jewish beliefs.
I generally don't bother trying to explain my hypothesis to people unfamiliar with the details of the Shroud controversy, because to understand it requires quite a bit of background information, inaccessible to most. But you seem to be one of the more informed sort, so I don't mind giving you the essence of it.
If you understand the postulated relationship between the Shroud and the Holy Mandylion, you're no doubt aware of the Byzantine history (or histories, because there were two separate accounts) that attempted to account for the origin of the latter. Those histories were somewhat disparate in nature, but the one element that each had in common was the assertion that the Mandylion was associated with a so-called "tile" (keramion, in Greek) that contained an exact duplicate of the image on the Shroud. In one of those histories, the cloth was found outside the city of Hierapolis inside a collection of tiles, one of which contained the exact likeness of the cloth. In the other, the cloth was discovered inside a niche in the walls of Edessa, in the company of the tile, which was later given to the city of Hierapolis. The tile is associated in both accounts with the cloth, and the city of Hierapolis.
Wilson postulated that King Abgar V of Edessa had caused the holy (cloth) image to be placed above the city gates in the place of the pagan image that had existed there previously. He postulated that, following Abgar's death, the city reverted to paganism, and the cloth was bricked up inside the wall for protection, not to resurface for several hundred years, when it was accidentally discovered, along with the tile.
My hypothesis (not "theory") is that Wilson's idea is partially correct--only, it was not the cloth that was placed above the gates, but a piece of statuary. When it came time to cover up the image (for whatever reason) a cloth was hung in front of it, and over a period of several hundred years the three-dimensional image from the "hard" prototype became transferred to the cloth through the agency of ionizing radiation originating from radioactive elements that are present to varying degrees in all sedimentary rocks ... the extent to which such ionizing radiation would affect the cloth being a function of its distance from the prototype.
I'll leave it to you as to whether this hypothesis is worthy of consideration, but it's interesting to note that in Ray Rogers's recent paper he mentions the effects of background ionizing radiation on linen and its role in the linen aging process.
It's interesting, too, to note that these shroud "researchers," are willing to embrace any theory, no matter how far-fetched (see Schwortz's website for the past five years) that tends to uphold the idea of the Shroud as a genuine relic, but refuse to deal with any thought that might hold it up to a different light. People like Schwortz and Wilson can probably be forgiven for this, because they're not scientists, nor do they pretend to be (unless the constant repetition of the words "peer reviewed" qualify to lend that distinction) but others, like Jackson and Rogers, should give up any claim to the title, at least as regards the object of their adoration.