The problem with Mormonism's claims (and I suspect all faith based ideologies) is that they normally assert things that they cannot possibly know about and are then shown to be wrong (often many years later) and that which they stated (normally with some God's blessing') ends up being plain wrong so discrediting the whole structure. Science is a different thing - it is a methodology to evaluate observed phenomenon and create a model to describe it - it requires skepticism, rational thought, peer review, tests and so forth. It doesn't attempt to answer every question nor does it place a marker in the ground that cannot be moved ( no one gets put to death for questioning dark matter.)
Mormon prophets have stated some absolute howlers that completely negate their ability to claim truth. A non Mormon prophet who completely fooled me was Paul H Dunn. When I listened to his stories I was filled with the 'Spirit' and was amazed by the truth I was learning about God's dealings with mankind. When I found out he was lying all along and making money from his books and talk tapes I had one of many mini faith crises that ended up on the shelf. The spirit confirmed teh truth of something that wasn't. There is a lengthy list of Mormon failed truth statements such as the age of the earth, the global flood, the animals on the American continent, the nature of light and how the Sun shines, Egyptian alphabets, interpretations of a Greek Psalter, Hoffman forgeries, how to cure homosexuality, the need to marry polygamously to get to the Celestial Kindom, the status of non-whites, ancestors of American Indians, how dinosaur bones got there, organic growth of Gold and Silver, monogamy causes society to fail, we will never get to the moon, Indians will become white etc.