Death of an AI command station by the player grants +15 AIP (and 5 for the warp gate), and then the player can build a command station for free.
A neutral (hostile to all) faction destroying an AI command station grants 0 AIP (by default), but will cost the player 15 AIP if they want to build a command station there.
A player destroying a recaptured station will cost 15 AIP if the player hadn't previously paid the AIP cost for the planet (so if it was originally done by a neutral faction). The player will then have to pay another 15 AIP to capture it, as the game still considers the fact that the original command station was destroyed by a neutral faction.
AFAIK all cases in which this sort of thing could occur have been fixed, and i'm not sure which of those this actually was. If this ever occurs again, please submit a save with it too.
