In vinegar we trust?

Tonight I was researching vinegar for my organic chemistry class (since vinegar contains acetic acid derived from alcohol, in case you didn't know or, eh hem, cared) and this simple topic led me to celiac disease, just as so many things in my world seem to do. About 2 months ago I had a celiac guest at the Restaurant to whom I recommended a dish that contained mayonnaise. When it arrived at the table she informed me that she couldn't eat mayonnaise because it contains vinegar, which is commonly made from fermented wheat or barley. Turns out Chef makes his own mayonnaise from rice wine vinegar, which completely delighted her and resulted in a happy ending. But I myself was left a bit lost by the encounter, since all of the books I have read insist that regular vinegar is free of gluten.

So in researching vinegar tonight I learned more about why it is technically deemed gluten-free: white vinegar (most commonly used) is made from distilled alcohols, which have been evaporated from their original source (such as beer) and recondensed as a more pure form of alcohol that will not contain any protein or "prolamines" (which gluten is). This is why celiacs are now told that they can drink vodkas, gins, whiskeys, and bourbons if they are 100% distilled liquors, even though they are orginally made from a wheat, barley, or rye source.

BUT..."old-school" celiacs insist that they get sick even from distilled products, which would include vinegar. This would mean that ketchup, salad dressings, mayonnaise, mustard, pickles, and many many other condiments would be off-limits. It would be tempting to dismiss these people by claiming they are "psyching themselves out", as though they get sick because they know it's from a gluten-source. Or perhaps all of these people simply drink too much alcohol and feel sick just like every other drunk! I do not think it is reasonable, however, to dismiss so many reactions. This makes me wonder if "science" does not yet fully understand the issue: perhaps some component of gluten remains in the distilled product which also triggers the celiac response? Or maybe contamination is at fault, even if the intended product is free of gluten.

Since I still can rarely identify my symptoms of celiac disease, it is very difficult to know how MY body is reacting, if I am having an immune response to all of these vinegars and alcohols without knowing it. Some celiacs get sick, others don't...so who do I trust? Especially when the former stance would mean MANY MANY more restrictions.