Sorry, but I still think you are wrong because James didn't say trichroic as you stated, he said trichloric which as you clearly know is a different thing altogether.
Maybe i'm confused because of the language used by so called expert websites, Gems TV says 'Tanzanite is a gemstone that really sparkles under any lighting condition. A pair of Tanzanite Earrings will display colour hues from light Periwinkle Blue through to deep ocean blues. It is also possible to view flashes of pink from gemstones set into a pair of Tanzanite Earrings,
as Tanzanite is a trichloric gemstone.
Jewellery Africa say it is trichloric too, maybe they are not being specific and if so I apologise but they both seem pretty clear to the layman, nevertheless I am certain James didn't say Trichroic. Far be it from me to defend him but in this case I don't think he is guilty!
http://jewelafrica.com/tanzanite/choosing-tanzanite/