As far as I can tell the values are inverted.
4.8.2.2.1.1 Occupancy Attribute
The Occupancy attribute is a bitmap.
Bit 0 specifies the sensed occupancy as follow: 1 = occupied, 0 =unoccupied
enum zb_zcl_occupancy_sensing_occupancy_e
{
/*! Occupied value */
ZB_ZCL_OCCUPANCY_SENSING_OCCUPANCY_OCCUPIED = 0,
/*! Unoccupied value */
ZB_ZCL_OCCUPANCY_SENSING_OCCUPANCY_UNOCCUPIED = 1
};