I'm not sure of CP's priority baggage handling policy, we at AC have been told to handle all CP/AC priority the same. (Last on First off and delivery to the priority baggage Carousel. We will not deliver the 'regular' bags until we know all priority is in.).
In saying that there are always going to be failures due to originating stations not segragating baggage properly. We do find tagged priority mixed in with regular economy baggage. We inform the bag halls as to the status when we find them... Management is also informed and they must follow up on the failure.
By no means am I trying to make excuses for anyone but alot of problems do stem at stations where we do not handle our own baggage.
I hope that this does enlighten the baggage handling process.
Regards YYZAC