You’ve a fine interpretation. But the law is clear and makes no such distinctions.
I think most of this kerfuffle is the awkwardness of verbiage in Texas law which does not comport with what most people understand to be the norms in law.
I've also pointed out to Bubba Ho Tep that the definition he quoted of Texas statute doesn't seem to have any provision for people who shoot and kill people for lawful reasons. (Like protecting their own life.)
A straight reading of it asserts that anyone who kills anyone for any reason is a "murderer", and that is clearly not correct factually.