You are mistaking legal disclaimers from reality. Just because labeling laws have certain requirements, for example foods made in facilities that also use wheat, that doesn't mean that those products contain wheat. In fact, products made in facilities that produce wheat might test negative while some made in gluten-free facilities might test positive. Many products, even ones with gluten-free certifications, have tested positive for gluten. How does this happen? Just because you have a gluten-free facility doesn't mean that the facilities where you get the ingredients are also gluten-free.
Once again, the beer tests gluten-free using what is considered to be the industry gold standard for such testing--the R5 Competitive ELISA. I have no problem with them making the claim it is gluten-free, and do understand that they must juggle a ton of contradictory state and federal labeling laws and essentially walk a tight rope to be able to manufacture and sell this product to their target market.
We are only in round one of the USA labeling laws, and I suspect that round two will include such products as gluten-free.
Also, not to totally discount anecdotal evidence, but there are lots of people who are super sensitive who claim lots of interesting things that can't be backed up by science--for example that distilled spirits made from gluten grains contain gluten--no scientist who understands the distillation process supports this, yet we have similar claims.
One thing I do know is that those who believe this beer is harmful should not drink it, but for the rest of us products like Omission are exactly what we've been hoping for since being diagnosed.