That is absolutely untrue. It's pretty clear that Buzz was inspired by Brightkite. I'm not going to pass judgement on the similarity, but the inspiration is clear.
How come? Given that every UI element on the iPhone is standard. Apps having similar functionalities are bound to look alike.
I think you have two things:
1. Google developed their library of UI elements that looks a lot like the iPhone ones.
2. Using that library, they made a new interface for Buzz. It does look very similar to Brightkite's, but only the location part can be really argued as "inspired", the rest is pretty standard indeed.
Not that there's necessarily anything wrong with that.