That seems to be the point of modern propaganda. It's no longer about trying to convince people of what to believe in. Instead, the idea is to throw out multiple competing ideas no matter how far fetched to breed cynicism and conspiracy theories.

I tend to read RT.com from time to time when Russia is featuring in the news to see what the Russian media is saying. And I have to confess the barrage of conflicting information (vis a vis western media) is extremely disorienting and difficult to methodically process. I'm not surprised that some people feel the way that you do.

What I would also add is it's interesting to note how the story is pretty consistent from western media (that rebels shot down the plane by mistake). From what I've seen, the Russian media perspective is highly fluid; i.e. prone to change and multi-pronged.