Unless you got the seller's permission to bid, you shouldn't have bid on the US only item. It is not uncommon for sellers to file an unpaid item dispute against someone who is not in their ships to area who won their item. It is a way to get their final value fee credit. Sellers can send transaction cancellations to the buyer but they run the risk of the buyer declining the cancellation and the seller will still have to pay the fees.
In the future, pay close attention to whether or not a seller ships to Canada.
Non paying buyers deserve unpaid item strikes.