Yesterday I needed a product in a hurry, so I chose an item that had 8 in stock and that stated "Ships from and sold by Amazon.ca". Then I chose "Express Shipping (averages 2-4 business days")
Today my order has shipped and the item now says: 7 left in stock.
The catch is that the tracking page says: Shipment has left seller facility and is in transit Columbia, SC, US. Expected arrival is in 7 days. So its not stocked in Canada at all. I haven't had this happen to me before. Usually they just hide the fact that their third-party seller is located in China.
Oddly enough Amazon.ca does not give you a place to review them or complain to them about their policies.