This is the first time I've had this issue, but it has me a bit scared now to cut any of the other expensive figures lumber I need to work on. This neck is longer than 24" so it was being milled on a diagonal line (hence the finishing path pattern). However, at the very end of the absolute final path/cut something happened. I don't know what as I wasn't around for it... but it looks like the x-axis lost some steps and so things started cutting too right right. As you can see the roughing pass did just fine. I have also re-tried this file in some scrap and it worked fine, just like all the other times I've run it.
What would cause something like this?
How can I avoid this in the future?
Any help that could put my mind at rest before I strap more expensive guitar wood to the table would be greatly appreciated!

Chris