Your critique makes no sense. It was a retrospective chart review with no control group looking only at cardiac rhythm. Your point that it did not show significant improvement in survival makes no sense, that's not what the study was looking at and it was not designed to determine improvement in patient centered outcomes since there is no control group. The point of my post is that there is at least some evidence (albeit low quality) that appears to demonstrate some potential benefit to narcan in cardiac arrest. You will never get a prospective, controlled study because it would be inappropriate to withhold narcan in an opiate related cardiac arrest.
If you'd like to put your liscense on the line withholding life saving medication due to an opinion lacking any evidence, just know that you will have very few physicians that would back up your opinion, and plenty that would be willing to testify against you. When there is no way to make a patient more dead by giving a medication and that medication is strongly recommended and has a theoretical benefit, you'd be insane not to give it. Do you withhold ACLS meds, too, despite their proven lack of efficacy? Somehow I doubt that you're telling your nurses to hold off on the epi in a cardiac arrest.