You, sir, do not understand the law if you think that the phrase “I’m gonna kill ‘em” followed by the act of actually “killing ‘em” doesn’t constitute any more than hyperbole. Such utterances are used as evidence of intent at trials all the time. Are you of the opinion that we should never be able to use someone’s stated intent to kill as evidence of their intent?
Not when an EYEWITNESS says otherwise. You just keep forgetting that minor point. The guy acted exactly correctly according to Texas law (and the law of sanity).