Why would it be a "stretch"?

The basic requirement is whether the source code is available - and made available. Are you certain that Google's solution here is ensuring that the source code is easily made available? So many other projects just provide a wget-able link. Why does Google want to make it harder to obtain the source code than those other projects?

> Android has always been more source-open than “open source”.

And what exactly does that mean? I don't know what your words mean here. More source open than open source? Is that a tautology?

> Everything else is essentially all the work of Google and (to some extent) Samsung.

Is it GPLv2? If so then I fail to see why anyone should get higher rights. Everyone gets the same for GPLv2. That's the whole point. I don't understand your statements here.