Yes, you were right about Federal Court not being the best venue! CN was saying that, but they had such a stake that I believe the AGC submission is something of an impartial, law-based viewpoint saying it was a commercial, contractual issue upon which VIA and CN had previously agreed on the framework.
And yes, the public disclosure of the documents, (pointed out to me by VIA!) showed this layman that there is no smoking gun from CN, that there is no data that widely and conclusively proves their point, and that CN's position is based on US experience and risk-aversion rather than purely crossing safety.
The fact that CN wanted to make its crossing data submitted to Transport Canada marked 'CONFIDENTIAL' says something. There's either nothing there, or perhaps there's something there, that either way CN doesn't want the public to be able to see.
Corporate egos notwithstanding, the big loser here is us, the taxpayer and us, the passenger. VIA's reputation is suffering age the hand of CN, and the implementation of their shiny new trains severely blunted. At a time when VIA did not plan the implementation well, did not have purpose-built shops ready, tried to push the Ventures into Southwest Ontario with its slow track, all the while fighting CN over its Train Service Agreement.
I'm expecting further documents, as well as ATI responses. There are indications that VIA management is reading lay sources for information, like this!