RE: hysteresis or other effect
Yes I know the battery is disconnected, so my best guess is all the tiny capacitors within the circuitry may have some left over voltage from when you last run it, but you say your brake is off by default, so I'm kinda puzzled. Also, don't forget that when you rotate the shaft you are creating a small amount of electricity (like a headlight dynamo in a bicycle) so that may somehow provide some power the ESC needs to "go into action."
About the brake, are you sure when you cut the throttle the prop just coasts to a stop or does it come to an almost abrupt stop (like mine does with the brake on)? [sm=confused.gif] Also, when powered up, if you have yout throttle at 0%, when you try to spin the prop by hand (at your risk) do you feel that same weird resistance or does it cog normally?