Relevant mechanics, for those lucky enough not to have dragged their ballsack through the broken glass shards of Dominion sov:

• While an infrastructure hub or a station belonging to an alliance is online, and a territorial claim unit owned by the same alliance is online, the territorial claim unit is invulnerable.
• After an infrastructure hub has had a shield and armor reinforcement timer and reaches 0 hitpoints, it explodes and dies. Infrastructure hubs cannot be placed while there is any kind of sovereignty blockade activity in the system.
• When a station falls below 0 hitpoints, its ownership is transferred to the corporation of the character who landed the killing blow.
• If the sov defenders "ninja" the station by getting the killing blow, AFAIK it immediately heals and ownership is retained (the game "flips" it from alliance A right back to alliance A). The instant after that happens, the system will be vulnerable due to the online SBUs (which by definition are alive if the station just got flipped), and so the station can be pushed immediately into shield reinforcement if the aggressing force continues to shoot - but because of the station full heal after flipping, both shield and armor timer will have to be re-fought.
• If a 3rd party had ninja'd the station, then the TCU and the station would be "out of alignment" and both would be vulnerable to a quick grind'n'flip by a superior force on grid. So if goons (or w/e 3rd party) had landed the final hit on this particular station, the battle could still have been resolved tonight - the station could be re-flipped without any timers, the TCU burned, and a new TCU onlined.
  
• If the station was in fact ninja'd (and it looks like it based on comments ITT), I imagine PL rage-reinforced the station, meaning it will have a shield timer ticking away, and the SBUs will be invulnerable (as happens while another sov structure is reinforced), meaning another infrastructure hub can't be onlined (I'm assuming the system's infrastructure hub was killed before the final station timer, as that's the logical choice given the interplay of the mechanics).

(I definitely might have missed a detail or two there, sorry if so)