Without going to deep into it since I’m not entirely aware of the situation. Turning a blind eye and calling your customers liars is just bad business practice. I would assume something went wrong with their equipment and that can happen as a business owner you should deal with it and not by denying it.
What I would like to know how ever is. How many people found out by testing, how many did the testing after finding something wrong with their e-liquid and how many decided to test after reading about it. Last but not least how many died or got seriously ill due to nicotine poisoning. I’m sorry if this sounds harsh but the worst i see happening is my 6mg juice turns out to be 12 mg I notice fairly quick and complain by the manufacturer. That in this case the manufacturer handled it wrong/was a dick about it is again unfortunate.