Split the action "Steal Maps"
Stop relying on the Spy unit type flag to decide if the "Steal Maps" action consumes the actor unit. Split the new action "Steal Maps Escape" from "Steal Maps". The former will have its actor try to escape. The latter will always consume the actor unit.
This makes it possible to create a ruleset where all actor units, including those with the Spy utype flag, are consumed when stealing parts of a civilization's world map. It makes the opposite (everyone, including non Spy units, escapes) possible too. It also makes more complex rules possible.