copy/paste from my post in the feldberg video thread:
There is more to OAT than just verticle axis wobble. There is also horizontal axis OAT.
Picture the disc rotating flat without flutter... but instead the axis is not on the center of the disc. Think of a hammer being thown. The axis is not on the center of the handle, it's closer to the massive end. Or, think of the design/shape of the Aerobe Epic. It does not spin on center axis until it flattens out.
EVERY THROW has a brief moment of horizontal axis OAT because we hold the disc with one hand.
Probably not the best term, but neither is snap, and that will never go away.