UK DTLR regs state quite clearly that NO aircraft, irrespective of nationality may depart any UK aerodrome with unchecked baggage on board. Unaccompanied baggage that has been cleared with the relevant procedures may travel but is required to have an unaccompanied hold baggage certificate signed. If you do not have this certificate then it doesn't travel - period. Our company requires the loadcontroller to sign a different declaration stating that all baggage recorded is on board and that he certifies that no unknown baggage is loaded in accordance with our company regulations. If we don't have this certificate signed and presented with the loadsheet, then pushback does not begin until it is presented and signed by PIC.
Twice our aircraft have been recalled recently back to stand due to the procedure being missed, several knuckles being severely rapped. CX procedures sound very similar to ours.