Yes, I'm well aware. I'm responding to the code in the OP's article (you need to click through the link at the bottom of the HN submission--I have no idea why the OP blog has two separate pages for this).
The MRI example is perfect, but I feel like the yogurt one is a bad example given the "and sometimes Y" (is a vowel) thing, or do we just ignore that for a vs an?
Like in this context, do we always treat Y when pronounced like "Yes" or "Yogurt" as a consonant?