I hate having to do this. This is what I do. Tape it off from a good start at the stump. Then I cut the logs off from the top down to get rid of some of the problem/wait. If you think a chair is bad in a normal way, it's spooky as hell on the ground. Things will break, roll, twist, and plain ole be in a bad way all at once, usually a few going at the same time, in opposite directions. A standing chair you have some idea of what is going to happen, on the ground you have the immovable ground in the mix now. If you can break it down before you get to the stump a lot of weight is gone and less apt to go wild and with less force. When that wind came through on '07, there was a lot of this happening down way of the coast. Don't forget stuff on the ground when it gets to moving will chase you, depending on the ground, it may chase you for a long time. Be for sure you have more than one place to go when things get to happening, they seem to happen faster when your working this nightmare.
A couple tricks. If you can drop something(big) behind the root ball, helps keep it from having so far to go. Drop something on each side, helps keep the rolling to a minimum, buck all that stuff up first.. Kind of crib it up. If nothing else it will give you a possibly better place to stand when the inevitable comes and you have to make your cut at the stump. If you have to, short log the butt section, take the wait off the top and if you short log it sometimes it will stand up a tall stump you can cut normal. Short logs be darned if it makes it better and safer.
I don't know if this helps anyone. I do know at the end of the day you will wish you was still a drinker sometimes though, and you will flat whipped. One good thing though, it's already a pile of pick-up sticks, so what you do won't make it much if any worse. I feel worse for the loggers than the cutters in those messes.
Owl