^I'm not saying there's anything wrong with examining the details of a work of fiction. As I've said, anyone familiar with my Trek writing knows I'm the last person who'd have a problem with examining the details. I'm just pointing out that the word "canon" refers to a holistic concept rather than a reductionistic one. Asking if a single detail is "canon" is like asking if a single thread is a tapestry, or if a single dot of color is a Seurat painting. The canon is the whole thing, and the details of the canon may or may not be consistent with the whole. Often a canon is an impressionistic thing -- you have to step back to see it as a cohesive whole, because on the detail level it can look a lot rougher or less meaningful.
So it's certainly worth evaluating the creation of the fiction on a detail level, because that can be illuminating about the process and can provide some interesting background insights. Or it can provide material that a novelist like myself can build stories and characters on. But one has to be flexible about it and recognize that some details aren't meant to be taken literally. Film is illusion, and often the illusion is ruined if you examine certain details too closely. (The "canon" of a magic trick is that the assistant is levitated, not that there's a hidden pole holding her up.)