I've heard of places importing live rock into Canada before without the permits and perhaps it's a case of "sometimes you get lucky" and "sometimes you don't." I don't really know. I know I've heard stories up people getting caught trying it, and both importers and exporters getting into a world of hurt because something wasn't legit ... but all I have is hearsay.
At any rate, this is what I do know. In general, all stony corals are, I believe, listed on CITES Appendix I & II. This means at a minimum, a CITES permit from the country of origin, or a re-export permit, must accompany the shipment for it to be legally imported into Canada.
I should mention that CITES is the "Convention of International Traffic in Endangered Species" and it should be noted that essentially every country in the world has signed this treaty. For more info see the links below.
Appendix I are species at the highest risk, and basically there is no legal traffic in this species, except for exceptional circumstances (e.g., medical research).
Appendix II are species at risk but not as high a risk as Appendix I, therefore traffic is permitted, but only with the appropriate documentation in place.
I think the complication for live rock is that it is not a specific species. However, the CITES treaty does not differentiate between alive or dead, whole or parts thereof. For example, boots made from the skin of an animal listed on Appendix I are a controlled item. It doesn't matter that the animal is already dead. Also, seeds of an endangered plant would also be a controlled item.
Thus, being that live rock tends to "dead coral covered in live invertebrates", it follows to reason that it really is a controlled CITES category.
That said, I've been having a dog of a time trying to find a website that proves this assertion. It's really easy to do a specific species lookup in the CITES database; it's not so easy to use vague common name terms.
I suppose there's always the possibility that live rock has been de-listed off CITES. Who knows.
Or maybe this place just happens to have the correct documentation.
Anyhow, for some further reading if you're interested, check out the following links:
http://www.cites.org - CITES organization web page
http://laws.justice.gc.ca/en/E-19/C....32/101487.html - Import of Specimens (Personal or Household) Permit
http://www.cites.ec.gc.ca/eng/sct0/index_e.cfm - Canadian government website on CITES
http://news.fws.gov/coral.html - a US government page on the coral trade