I'm not an expert on the Android platform, but here's my take. Apps downloaded via the Android Market are tied to your Google account. That way, you can move between devices and not have to re-purchase any paid ones, or have to deal with the headaches of re-downloading freebies. So, in that way, you could say that Android has a backdoor to Google.
That said, you can install apps from non-Market sources by simply checking a box in the Settings. Install the app from any other avenue besides the Market, and Google can do naught. The issue about this app is that it was distributed through the Market, which is its own trusted source.