The source of fat coagulation in the two types of milk is different. In non-homogenized milk, the particles of fat have nucleated to a large enough size that they will clump together, despite the presence of surfactant (casein). In soured homogenized milk, the reduced pH caused by the bacteria digesting lactose protonates the anions in the casein, ruining their surfactant capabilities. As an example, a little bit of lemon juice or vinegar will cause milk to similarly coagulate. So, if you want to be scientific about it, you can check the pH of your milk. Or, you can:
You know lactose intolerance is due to drinking pasteurized milk. People who are lactose intolerant can drink raw milk with no problems.
So much cause and effect fail here. The lactose intolerance isn't due to drinking pasteurized milk at all. The reason that some people who are mildly lactose intolerant can ingest raw milk is that some of the lactose has already been digested for them by the bacteria present in the milk. That, however, is the equivalent of saying that spoiled milk is better for you.
Edit: I should also note that this is why lactose intolerant people can also eat yogurt. Yogurt is a living culture of lactose-digesting bacteria, which in addition to digesting some of the lactose in the yogurt, also colonize your gut and help with digestion of other milk products.