This title (the one from Engadget) makes it sound like someone bypassed Google's security to get access to the e-mail account information... the users were phished, and so this is more like "Google warns" or "Google explains" rather than "Google admits".
A good deed rarely goes unpunished. I bet that 90% of newspaper headlines on this matter made the same intentional choice of making it sound like a failure on Google's part. So it turns out that the standard large company instinct of covering up anything even vaguely security related is exactly the right thing, and disclosing this stuff is just for idealistic fools who want to be torn apart by the press.
If someone tricks you into letting them into your house, beats you and steals your stuff that does not mean they broke in.
Phishing != hacking the weakness here is gullible humans not a system breach. The post is optimized for max bait-ability.