The following notice has just been published to cxagents.com. The Canada exception is gone - now you have to ticket in the country of origin if you want the lower price.

"ONEWORLD Fares Local Fare Check Revise

PLEASE BE ADVISED THAT ONEWORLD FARES LOCAL FARE CHECK EXCEPTION FOR CANADA IS DELETED. THE FOLLOWING FARE CHECK WILL APPLY TO SALE WORLDWIDE WITHOUT ANY EXCEPTION WITH IMMEDIATE EFFECT.
TRAVEL ORIGINATES IN A COUNTRY FOR WHICH A SPECIFIED LOCAL CURRENCY FARE IS PUBLISHED AND THE TICKET IS SOLD IN ANOTHER COUNTRY THE FARE WILL BE THAT PUBLISHED FOR THE COUNTRY OF ORIGIN CONVERTED TO THE CURRENCY OF THE COUNTRY OF SALE AT THE BANK SELLING RATE. THE RESULTANT FARE MUST NOT BE LOWER THAN THAT FROM THE COUNTRY OF SALE.

EXCEPTION - WHEN THERE IS NO SIMILAR FARE EX COUNTRY OF SALE FOR COMPARISON CONVERT THE ORIGIN FARE INTO CURRENCY OF PAYMENT BY BSR.

ONEWORLD EXPLORER FARE, ONEWORLD CIRCLE TRIP EXPLORER FARE, ONEWORLD CIRCLE PACIFIC EXPLORER FARE AND GLOBAL EXPLORER FARE CODNITIONS WILL BE REVISED. SYSTEM WILL BE UPDATED. THANK YOU FOR YOUR ATTENTION."

Sorry for the shouting - it's a direct cut and paste.