Yeah, this sounds like just something else they can tack onto another charge.

Reminds me of the laws, here in Missouri. We have the "armed criminal action." Basically, if you commit a crime, and you have any sort of weapon in your possession, it's just yet another crime they can pin you on.

So, I see this as whatever drug-related charge PLUS tax evasion. Just another needle to stick in them (pardon the pun).