I once worked with a digital marketing manager that spent most of her day running scripts to spam Digg and Reddit, and using her budget to "outsource" these kind of things (probably using Mechanical Turk or something similar). She'd worked at marketing agencies before, on a number of large client accounts (including notable names in tech and consumer electronics), and I'm willing to bet that she did the same kind of stuff.
They may have guidelines in place, but I bet they don't check up on what external agencies do, otherwise this woman would have been found out a long time ago.
Wasn't there an awful ad from Samsung or some big company recently, and they had to pull it and apologize for it, because it was very offensive, and they had no idea what the ad would be prior to being on TV? (or at least that's what they claimed).
Either way, I don't think it's that hard to imagine. These companies, especially mediocre companies who like to "outsource" stuff and not care as much about the result, pay millions of dollars at a time, and don't look into all the details of the advertising campaigns.
They hired a small army of commentators to trash HTC and talk up Samsung in blog comments etc.