Weird Google Adsense issue – customer service provides very vague reply

A friend of mine, Karen, who runs Coolmath.com, sent me a weird advertisement she saw on her site as part of her Adsense block. (image on right) The ad was FOR her site, but ON her site.  It did, indeed, click over to Coolmath.com and the phrasing in the ad was straight from her site.  But, this ad was NOT from Karen's AdWords account.  Not even close.  She did not set this ad up and the ad advertises her own site ON her own site!  Karen wonders if some benevolent billionaire who's a big Coolmath fan bought this ad.

No one on our advertising message board could figure out why anyone would setup this type of campaign. After a day of trying to figure out why this ad would appear, Karen contacted Google Adsense support.

After A WEEK of waiting for a reply, she received the following reply to her inquiry about the weird advertisement:

Thank you for reporting an ad that may violate one of our policies. We have taken the appropriate actions for the account.

I am a bit disappointed that they did not share any other information about what happened. We know that Google is tight lipped about their policies and practices, but to not even confirm that there was a problem is really leaving the question open. Their use of the word "may" in the reply message means that the ad actually might be ok!

While the only idea I could come up with is that the ad was a mistake in the URL and an oversight by the person setting up the ad, I am interested in see if any of you have ideas about why this ad was created. Could something malicious advertiser be behind it?