WORST case scenario, if you dumped your nand, and turned it back on with the stick in the machine, it would write the same nand it already had on to the box again.
That's assuming you are dumping your nand as updflash.bin. and it's starting from Xell.
Otherwise, yes, spaz2203 is quite accurate indeed. You would have 1) A Dumped nand, and 2) An xbox that has been turned back on.