he resigned because of... "politics"? and not because of the path Google has chosen for Android security?
One of my favorite 80's movies was Real Genius with Val Kilmer. He accidentally helps develop a weapon and then goes to extreme measures to prevent its use. For some people creating weapons is a line they wont cross and that's not a bad thing.
Would the author have left if they didn't have another job lined up? Definitely not. Then, how strong are their principles?
That's not remarkable to many.