It's a question of how the legal threshold must be satisfied under the legal system, under the courts, and comparing that to the type of international arbitration provisions that are typically part of trade agreements. It's a much different standard. For example, in labour arbitration we deal with the balance of probabilities as opposed to absolute truth, and that relaxes the standard.
I have a background in taking some international trade courses during my academic career. I have a thick book of jurisprudence on international trade tribunals and decisions, and some of them make as much sense as some labour arbitration cases do on either side, whether you're on the employer's side or the union's side. I think just relaxing that standard and the provisions that apply, and ceding Canadian jurisdiction over that matter to a panel of arbitrators is a very tricky proposition under any circumstance.