In the present case the owner of the aircraft could be at risk from claims where they allowed someone who seems to have been without a licence for some years to hire an aircraft. The organisation concerned might also face criminal liability. Whilst they may not have been aware of the positio they clearly should have been.
Justiciar, it appears that the pilot was also the owner, so this would not apply here - although you are undoubtedly correct should he have been hiring.
FBW