When the phrase is used in everyday speech, in my experience, it's usually true. I went to the local grocer and "it turns out" (meaning, I checked and I asked and) they don't carry such-and-such. That's what makes it such a powerful device: there's implicit trust when someone claims to have done the research.
But it's a two-edged sword. If you make a habit of abusing the phrase, and it turns out you're demonstrably wrong on occasion, opponents will begin to view the phrase with extra suspicion, and hammer you on not providing the actual "it" that turns out.
I second that. Use this kind of speak with people that are aware of rhetoric, neuro-linguistic programming or non-violent-communication (for instance) and you will shoot you in the foot deep.
"Incidentally, am I alone in finding the expression 'it turns out' to be incredibly useful? It allows you to make swift, succinct, and authoritative connections between otherwise randomly unconnected statements without the trouble of explaining what your source or authority actually is. It's great. It’s hugely better than its predecessors 'I read somewhere that...' or the craven 'they say that...' because it suggests not only that whatever flimsy bit of urban mythology you are passing on is actually based on brand new, ground breaking research, but that it's research in which you yourself were intimately involved. But again, with no actual authority anywhere in sight."