Faterson's right, it is a bug basically, and here's what skewed the average initially. About a month ago that player had a 2 recorded as a score, check it out....
I was the one to report this initially (I think), so that's the only reason I have the pic.
A 2 will skew your average a good bit. It'll also immediately promote you to the master tier. Obviously the 2 was stricken from the record, but neither the average or the tier was re-adjusted. There's been no apparent activity since the 2, so I'd imagine this player was either banned or simply asked to create another account because it may not be possible to reset the tier manually.
*edit* Oops, there has been activity since the 2, so he's still around and stuck in the master tier.
That's my guess anyway.
Dhani shouldn't be on community spotlight either, but I can't remember if he still shows up or not.