I probably have more experience shipping lasers from Canada to the US than anyone else here.
Since a non-FDA-compliant laser is legal in Canada, you (the exporter) would not be liable for anything as far as the Canadian or US government is concerned. They would just take your laser and your customer would receive an empty box with a letter in it explaining what happened. Then, depending on how your customer paid you, they could either file a chargeback (credit card or paypal) or they would have to trust you to refund them if they paid with a non-reversible method (bank wire or money order). In all cases you, as the exporter of a product which is legal in your country, face no criminal or civil liability. The importer could, however. It would be almost impossible for the buyer to sue you since he would have to declare, as part of his court case, that he was attempting to import illegal goods. This would be like trying to sue somebody in Columbia because you didn't get your cocaine.
The examples of court cases listed above are domestic transactions. International business works differently because we in Canada cannot be subject to American laws.
