If a ship is in standdown in port, its resources (platform) belong (resident) to the port, so it can be killed by A2G.
If a ship is in standby in port, it retains its resources, so it can only be killed by surface adjudication (maritime air).
Before departing a port a ship must be in standby. If the ship was in standdown, going from standdown to standby takes a user-defined period of time. During the transition from standdown to standby, the resources still belong to the port and can be adjudicated by A2G.
As late as R2.0 SR2.01, when a ship departed the port, it was leaving its resources in the port. Thus, the ship could be killed by an A2G strike on the port even while the ship is out to sea.
Inconsistency: Standby in port is sometimes adjudicable by A2G, and sometimes by Surface Adjudication.
Proposed fix in DTRA release: When departing underway, it draws resources at that time, rather than while going from standdown to standby.
Interim solution: Avoid putting ships into standdown. It's more effort to arrange the transitions between standdown and standby anyway, so unless it is a scenario requirement to be able to kill them via A2G, standby is easier.
Longer term solution: More consistent handling of resource accounting so that ships are adjudicable by Ship Adjudication while at sea, and by both Ship Adjudication and A2G while in port.