Spy bugs ... again

On the fates of spies on planets that change hands:

1) If one puts spies on a planet and then invades it successfully, then the spies return to the pool for re-use.  I've had this happen many times, of course.

2) If one puts spies on a planet and then that planet is invaded by a DIFFERENT race, then the spies should return to the pool as in #!, but I have never tested this.  The next time I see a planet about to be invaded, I hope to remember to test it.

3) If an Empire surrenders or is conquered, then planetary spies are also "refunded".

4) Empire "box" spies do NOT get refunded upon destruction or surrender of their target Empires.  To quote Loupdinor, they change careers and become archeologists on their specialty race, and even continue to send back useless reports.  The Dreadlords are not an exception.

What happens to planet spies when their planet revolts from its Empire?

I ask because of what I think I just observed in one DA sandbox game.  I noted a number of influence-vulnerable planets and put spies on them to damage their approval/morale, targeting morale buildings and ongoing upgrades.  Even without the MCC (which is broken in DA, of course), I managed to get many of the planets to become unhappy and to then soon join my Empire.  However, the spies did not get refunded!  I seem to have lost about 10 spies!

So,

5) What happens to planet spies when their planet revolts and joins my Empire?  Has my experience been seen by others?

6) Does it make a difference if the planet revolts but merely shifts to a different "other" Empire?  For example, would the spies remain where i had put them on that planet?