As far as I am aware, all the official looking blotters, with the well-established molecule-one-side-&-1P-LSD-the-other, come from one source lab here in the UK. The compound is sourced from various chemists abroad but it's all being vended from the main, known UK source. BUT! There is nothing to suggest that those blotters are impossible to copy. There is no way of preventing someone from having the blotter copied & flogging it cheap to unknowing new vendors. Not everyone out there vending compounds has decades of experience. Some of them might even be naive to these drugs & vendors of drugs they don't use personally. They might not have any idea they're vending duds.
Something similar has apparently happened with Al-Lad too. If it's a genuine thing, I wouldn't be surprised if a single individual were behind both cases. But as yet I have seen nowhere near enough evidence to assume that anything nefarious is afoot & I have every reason to assume that the vagueries of Psychedelic drugs use are behind anomalous reports of "inactivity"...
Even if some lab were able to prove that a tab or even a number of tabs were completely free of active ingredient, there's nothing to prove that the tab was not deliberately leeched of it before it was sent in, though why anyone would go to such lengths to discredit a vendor is beyond me... I can guarantee everybody one thing for absolute certain. If a sheet or two of completely inactive blotter has been circulated by the original & only known source, there is no chance whatsoever that it is deliberate scammery. It's a mistake. If it's happened, it's a mistake. Everybody makes 'em. If I got hold of a completely inactive blotter that might mean something, because I source my blotts from one person only. But I have never had an inactive blotter & I seriously doubt anyone with the reputation you describe would engage in selective scamming, which is what reports of inactive blotters are effectively accusing...
I'm sure anyone trying to dent the vendor in questions reputation is well aware of the fact that the accusation is almost impossible to prove & that's why they make it...