Was running around enemy base on juice and I somehow got stuck inside the ball area. Didn't have FRAPS on to capture how I got inside (think I was just bunny hopping with gold speed), but turned it on to record the effect at least: http://www.youtube.com/watch?v=trfCKhoQ-2Y
This sometimes also happen when you as a gunner fly and land on a teammates head., seems to be a collision issue.
Oh wow. I've had this happen to me once post Spunky with the 360 version. Sadly I ended up being stuck there for a good 5 minutes and it was my own teams moneyball.