Since no one has mentioned it yet, given the author felt like Japanese tea was providing a calming / anti-anxiety effect but with a much lower potential dose of Theanine....I wonder what would happen if he repeated the experiment with a sub-lingual dosing mechanism?

It seems like this would be closer to taking the tea in your mouth and savoring it over multiple sips across a few minutes, and could explain the smaller apparent dose having an effect (some of the Theanine goes straight into the bloodstream and bypasses the digestive tract).