The fundamental problem here is that we have allegations that the US Government ordered all these companies to do something bad(tm) and not talk about it. So,

The fundamental problem here is that we have allegations that the US Government ordered all these companies to do something bad(tm) and not talk about it. So, if we assume that the allegations are correct, then the companies denying it are in on it, and the denial is false. But if the allegations are not true(either wholly or just for Google), then their denial may be entirely true. That's why it's problematic, because if you believe that the reports are true, then Google's actions are perfectly in-line with that belief. If you believe they're false(or even not as extensive as reported), then Google's actions are perfectly in-line with that belief. So realistically, the best approach is just to wait and see.