The UK has already admitted they possess the same nerve agent at Porton Down. And the whole point of Novichoks is that they can be easily produced with easily obtainable materials--week killer, pesticides etc. A simple lab is required and a considerable knowledge of chemistry (about a Masters degree). What the "developer" says and reality seem to be entirely different things. Russia was intensively monitored and was declared free of all Novichoks at the end 2017 (although of course that doesn't mean they couldn't have hidden some somewhere). Existing supplies were transported to Ukraine for destruction--however at least 3 other countries are known to have such agents in their possession. So your summary is flawed in several respects, and with regard to Russia's questions, they seem reasonable, so Im not sure why so many people are ridiculing them--I would guess internet silliness.