Do the sphero minis need to be loaded back onto the ground vehicle after they are deployed?

Do we need the sphero minis to be moved back onto the ground vehicle once they are finished clearing trees, or can they stay off of the vehicle instead?

According to the rules (pg. 19), to be considered parked, the Sphero RVR and Sphero minis must be fully contained underneath the fire station. They don’t specify that they are on the RVR underneath the station. I do not believe they need to remain on the RVR after clearing trees.