The use of the word "mistake" can be used by or assigned to guilty parties, in this case, Pearson, Nicholson and various forgotten, anonymous and deceased functionaries, to imply that there was not an easily discernible better way. Not at all the case here. This was outright negligence, incompetence, and neglect, genocidal in its impact.  Not at all a "mistake".  It's a very important distinction to make in assessing and assigning guilt to individuals who should and must be named.   Canadians will be going through the uncomfortable process of recognizing some past icons as having committed great and shattering evils.  Take the aboriginal point of view to help  understand.