Why doesn’t “Create a Clue Token” trigger Erdwal Illuminator

I understand that creating a clue token doesn’t count as investigating, but I don’t get why. According to the comprehensive rules 701.16a “‘investigate’ means ‘Create a Clue token’, so I would think that [[Erdwal Illuminator]]’s text is equivalent to “Whenever you create a Clue token for the first time each turn, create a Clue token an additional time. However, this is not true (according to the TLA release notes and others.) What is the relevant rule(s) for this interaction? What other cases are there where a keyword is not functionally equivalent to its rules text?