What I stated was that science's reliability was impermanent [as are all things intellectual]. I am not sure what this has to do with what can be studied. Zen is simply being present. This is a non-intellectual endeavor and cannot be analysed using a traditional scientific method [although there have been some studies carried out on what happens in the brain during deep meditative states]. The outcome of such practice becomes manifest in one's perceptions and actions.
Sure, we have many methods for assessing and improving reliability, and understanding under what circumstances something is reliable. This doesn't really address the fact that so far, your other methods seem to have nothing of the sort, and will likely often simply be wrong.
This is where many people get stuck. It's experiencial, not intellectual. Many [actually, all] things are this way but we have intellectualized them to the point where we miss it. It's like being in the perfect moment with your love interest where you have been gazing deeply into each other's eyes, lost in time...then the spell is broken and somebody feels compelled to say, "I love you." The experiential connection between the two lovers was far and above saying something as pedestrian as, "I love you," but this is what happens when you go from the experiencial to the intellectual. It's the same thing with everything we do except we have supplanted experience with thinking almost universally. Meditation is a technique which teaches the practitioner to tap into the experiencial and summons the intellectual only when needed. Reliability is not an issue with pure experience, right? Reliability is only an issue when your intellect transforms perceptual reality into your personal reality. The intellect is completely different than pure experience, whereas the intellect renders an interpretation of your perceptions while experience-only is the real thing.