These are very good questions. Also, get ready for copyright trolling using these methods. The uneducated will pay.
As to your question, the answer is "no, you've done nothing wrong".
The image is may well be copyrighted in the US as in your example.
But, it's not a "copyright infringement" to host the image in Canada, as US copyrights don't have jurisdiction in Canada.
I know what you're thinking...
...what if Masterfile has the right to license the image in Canada, but Getty has the right to license it in the US?
...and you've bought the image from Getty in the US, but now you're hosting it in Canada... what then?
I haven’t read any passages in law or seen any actual court cases that address this (please chime in if you have).
But, I’m of the opinion that a copyright troll/extortionist (Masterfile in this hypothetical situation) would call this an “infringement” on the basis that they “cannot find a valid license for the image in the name of the end user in question”.
I’m also of the opinion that nothing would ever come of this; so long as the end user possesses a valid license (from the artist or a retailer) to use the image, then that should be sufficient.
After all, the “world-wide web” IS world-wide, after all.
Having said all that, people are stupid to use rights-managed images. They should choose royalty-free whenever possible.
The only time that rights-managed products are useful is when one needs an image to use as an exclusive trademark, or for exclusive branding.
Television and radio adhere to much stricter conventions in this regard, but it’s expected and understood to be the convention.
Additionally, “file-sharing” infringements appear to have taken on a world-wide scope, regardless of copyright, country, or local statutes.
People aren’t normally extradited from foreign lands to face trial in the US over major drug charges, or even murder.
But, when big money is involved, it’s an entirely different matter.
Don't expect this to happen in the case of stock images; the industry is shrinking.
S.G.