In the House of Trade, Dort's that proverbial merchant who's much more lenient about buying random garbage and gemstones. But I imagine that it's unintended that he buys/sells animal venom (and possibly other obvious contraband like arsenic and Animate Dead scrolls) which makes it a bit awkward to check in with him when playing a Watcher pc.
I'd recommend either marking poisons "Stolen" for him, or allowing the Dort smuggling ring to have a bit more subtlety.
Maybe he has a license!
Maybe indeed! Though it's illegal to sell contraband to people who don't have a license, and there's no reasonable way for npc's to check for that.
It simply seems easier from a mechanic standpoint to just mark those objects for Stolen.