"Crazy white man" was a term that was tossed around freely in the Mackenzie Delta when I was there in the mid 60's. It was thrown back and forth . White people used the phrase as well as aboriginal and when both groups were together. I'm sure that crazy white man was used in other circles in hatred.
I have no idea of the origin of the term but there were many situations that could have brought up it's origin. There would be a long history . European explorers came first, then whalers, missionaries, traders and government. All of them showed examples of not knowing how to cope and taking advantage of the original people.
One example of crazy will stay in my memory forever. I was not involved in this incident but have read and heard much about it. The Canadian government decided in the early fifties that Inuit in northern Quebec would be better off if they relocated some of them. The government decided that game was becoming scarce in the area and that relocation of some families from Port Harrison ,Quebec, would ease the situation on game.
So they choose 10- 12 families and moved them to Resolute Bay. These people were moved against their will. They were dropped off in Resolute Bay by ice breaker at the end of September with tents and a supply of food to get them started. Resolute Bay is one of the coldest locations in the Arctic. There is little game there. The modern Inuit had never been that far north.
These people suffered great hardship.
The real reason these people were moved was to be land inhabitants to claim sovereignty to the Arctic Islands. The early fifties was at the time of the cold war and Canada didn't want to find Russians inhabiting arctic islands. The Inuit called themselves human flagpoles.
I'm sure you would agree that this was a completely loony and heartless move by the Canadian government and it would deserve the term crazy whiteman.
Now there are countless more examples of what white people did to earn the label "crazy whiteman".