If you claim systems with the docked station, they will stay claimed even after the entity leaves the system.
If the docked station is destroyed, only the current system that its in will have ownership revoked, if the station own it.
Possible solutions:
1: Have the claimed system 'follow' the docked station, thus allowing only 1 system to be claimed at a time.
2: Have all claimed systems ownership be revoked if the entity is destroyed. (thus allowing multiple territory claims per station)