Anyway, this is just a hypothesis.
Lots of folks insist it helps one's placement in the SERPS to advertise with AdWords, and have ample evidence to back it up. Lots of folks insist that it hurts, and have first-person evidence for that as well.
As for me, I'll stick to "no connection" - and also add that coincidences of all types occur at the intersection of tons of advertisers and zillions of web pages. ;
AWA