The "well, they must have more buried somewhere" bit has been done to death. Also, you can go anywhere they mine gold or silver and get sodium cyanide in serious quantities, not some crappy cyanide salts that will require processing to make a serious weapon. There are a lot of other places to get varous types of cyanide. This is not indicative of a weapons program. If the guy makes a lot of ceramics it may not even indicate an insurgent, though I wouldn't bet on it.

Since nobody's going to waste a long range missle for a cyanide gas payload, the guy with the RPG is still more dangerous.