Unless you claim that the submitter is lying your whole 'Hey, nicely done by your PR department, Microsoft' argument goes down the drain.
But you have to be incredibly naive to think social media manipulation isn't a core part of companies marketing strategies today.
If you or anyone sees evidence of astroturfing on HN, please send it to hn@ycombinator.com so we can properly look into it (which we always do). We take the issue seriously, and it's also a serious breach of civility to casually sling these accusations at others. Two wrongs don't make a right.