Never knew about the Canadian atrocities.
Colonial Britain's worldwide empire of the past has always fascinated me from a military, economic and interestingly a botanical standpoint.
Those are huge topics, but contextually, the ability of the old British Empire to effectively use EXTREME brutality to grow the Empire, also led to the empire's demise. With limited exposure to something only extremely remotely similar, the ability to rise to that level of brutality, must have weighed heavily on their souls. But, given the time it occurred, I suspect that it was lessened by the mental attitude of being "British" and entitled. Most all of the atrocities were economically based as so were ALL of the colonies that were once a part of the British Empire.
But in world history, it was not unusual, just not to the final level that the British Empire.