I'll happily accept if im wrong as i am not a lawyer and certainly not a Canadian one, ive tried to find enforcement based on it but i can't find clear cases on it, this is the legislation:

No person shall manufacture, import, distribute, lease, offer for sale or sell any radio apparatus, interference-causing equipment or radio-sensitive equipment for which a technical acceptance certificate is required under this Act, otherwise than in accordance with such a certificate.

Radiocommunication Act 4(2)

The question becomes does "offer for sale or sell any radio apparatus" also apply to companies outside Canada?

Still, i can imagine a company is not keen on selling products they know are illegal in the destination country, but the seller (outside canada) being liable for the radio act is maybe wrong then.

On the consumer protection part it does seem correct that the foreign seller is on the hook, atleast for provincial law.

This Act applies in respect of all consumer transactions if the consumer or the person engaging in the transaction with the consumer is located in Ontario when the transaction takes place.

Ontario Consumer Protection Act, 2002, s. 2(1)

Again assuming "all" then includes foreign transactions.