The AdChoices icon is used by many ad networks, not just Google's, to indicate that there's per-user targeting happening. [1] But if you click on that "AdChoices" button and you get an AdSense help page.
I'm not too familiar with AdSense vs. DoubleClick vs. AdChoices, but when I hover the ad it shows a link to DoubleClick, the little triangle icon points to an AdSense support page, and the JavaScript to load the ad comes from googlesyndication.com. From what I understand, that all points to it being an AdSense ad.
I suspect the reason that kind of ad is allowed (despite being deceptive IMHO) is that it's not just a download link. It also indicates that it's an ad for a driver update site (which makes it even shadier to my eye, but probably not violating any policies).
EDIT: I guess AdSense is involved with AdChoices somehow. My mistake.