That one isn't really a node editor question, just a question on how Corona renders those materials :) The node editor is only a display / editing system, and not part of how things are rendered.
Didn't check YouTube yesterday, but I'd have answered your question with "please post to the forums" - YT is not a good place for asking questions as support and devs don't see it, plus you can't share screen shots, and having an ongoing conversation is hard and clumsy. Here is always the best place for any detailed questions!
(PS - I don't have answers to the questions, never tried the reflectance materials specifically, so we'll see what support and devs can add to the topic)