I recently fitted a centre stand, and like I said the bolts were hard to remove because of the loctite, but other than that I didn't have a problem. I don't think using grease on the bolts is such a good idea either
I personally think you have missed something somewhere, as lots of people have fitted CS's without this incident occuring. I cannot see how the bolt (if there even is one in there that can come loose) has come loose when all you have done is attempted to remove the bolt and then sheared the head off using only a circular motion.
Why don't you remove the bolt with the sheared head first, and then try again with a longer bolt? How can you be so sure the 'nut' has broken off inside without taking the bolt out first?