Gonzo, the ICAO definition of a critical area is:
The ILS critical area is an area of defined dimensions about the localizer and glide path antennas where vehicles,
including aircraft, are excluded during all ILS operations. The critical area is protected because the presence of
vehicles and/or aircraft inside its boundaries will cause unacceptable disturbance to the ILS signal-in-space
The ICAO definition of a sensitive area is:
The ILS sensitive area is an area extending beyond the critical area where the parking and/or movement of vehicles,
including aircraft, is controlled to prevent the possibility of unacceptable interference to the ILS signal during ILS
operations. The sensitive area is protected against interference caused by large moving objects outside the critical
area but still normally within the airfield boundary.
As per the definition, if aircraft are in this area, it cannot be a critical area