You keep re-defining the goalposts, but they’re your goalposts I guess so I’ll bite. I’m the kind of person that is very difficult to offend, and in turn views virtually no topic of discussion as verboten, infuriating as it is at times to those on both extremes of the political spectrum. 
My view is the deeper you dive into history (or any scholarly pursuit for that matter), the less certainty and conviction you will find.
I actually see nothing particularly controversial nor incorrect about @tsath’s observations, and I believe they can be backed up quite easily with the available historical evidence. Canada hasn’t undergone a civil war over slavery being one of the most glaringly obvious examples. I think those difference merit understanding, since the inform our understanding of the differences between the two countries today. In my opinion it would be nonsensical to conflate an appreciation of those differences with a fear they will somehow undermine an awareness of past wrongs. The two are mutually exclusive.
You seem fixated on this notion, completely subjective and unprovable as you appear to acknowledge it is. I don’t trouble myself much with such things actually. The weight of the world’s idiots is not for me to bear, although I assure you I am just as frustrated with them as you are. But I do strongly object to that fear being adopted as a premise to dissuade or limit any form of open discussion, be it scholarly or non-scholarly for that matter. I think the average Canadian is more aware of Canada’s racist past, including but not limited to the head tax, Japanese-Canadian internment, residential schooling etc., than the average American is aware of their own country’s failings. But I can’t prove that either can I? What if I created my own windmill to tilt at as a justification to limit such comparisons, say the fear that painting Canada and America’s colonial past with the same broad brush strokes played into the hands of American whataboutists, who could then exclaim “see it was just as bad there too, everyone was doing it, no biggie!”. Just as nonsensical and counter-productive isn’t it?
That’s pretty unfair. And you are misusing the meaning of that particular logical fallacy. I have not claimed any such authority as a matter of fact; what I have claimed is to having studied this particular topic at length and in depth however; one would hope that the examples I have given would speak for themselves.
In fact I cited two, the Nez Perce and the Sioux. I also gave the example that the N.W.M.P. was created in large part to protect the native population of the Canadian plains from the predations of American whisky traders after the Cypress Hills Massacre. By word of mouth among Plains people it was well-known that the 49th parallel was a safe haven, in that the ‘red coats’ were not waging wars of extermination against the indigenous population, as was happening on the American side of the border. That’s a pretty big difference “both qualitatively and quantitatively” don’t ya think? If that example isn’t enough for you I give up.
Finally
That’s a strange accusation to make. Adieu.
