Oh absolutely. It's an adversarial process. It's like civil court, in a sense.
The domestic producers would make their complaint, saying that because of the way they're priced or where they're sold, imports of rebar from country X or countries X, Y, and Z are causing them injury, causing them to lose market share or whatever the indication of injury is. The tribunal would receive that, would then notify everyone they could think of in the industry who would have an interest in this, and they would publish it in the Canada Gazette, calling for parties to identify themselves.
The opposition would also have an opportunity to put in a case, and eventually we would have a hearing. Both sides would be represented at the hearing, and both sides would have an opportunity to cross-examine and then make their argument.