It is not dumping if you are forced to sell below your cost of production it happens often. but when you bypass your own and your usual market and offer to sell for less than that market is currently paying, that is dumping.
Although you Canadians claim your concious is clear, that is why R-Calf filed their suit and proved that to be the case. They could not however prove that that had depressed the price.
I did not join R-Calf, and still won't, because I didn't believe they would accomplish anything with law suits. I did not know much about the Canadian cattle industry, and I still don't, but they claimed that the Canadian producer had several advantages over the US producer and could produce cheaper. They believed, and I guess they still do, that something needs to be done the level the playing field to protect the US producer. Some of the tactics they are using now do not set to well with me.