In The Apprenticeship of Duddy Kravitz, how is Mr. MacPherson affected by the death of his wife?

Mr. MacPherson is a teacher in Duddy's high school, and is a
victim of pranks by the boys. At one point, he insults Duddy's father, and Duddy takes the insult
very seriously. When a prank phone call results in the death of MacPherson's sick wife, he starts
drinking to excess and breaks a personal rule of his, that he will not use corporal punishment on
the students. This shows how much he valued his wife and how he felt that his life no longer had
meaning; he suspects that Duddy was behind the prank phone call, but has no
proof.

...it all came
tumbling down on Mr. MacPherson -- the drinking, the phone call, how Kravitz was master of the
classroom and he was being ostracized in the Masters' Room. A quiet little chat after school was
out...
(Richler, The Apprenticeship of Duddy Kravitz, Google
Books)

The effect is to turn
MacPherson from a target to a direct opponent; he takes pleasure in insulting Duddy and finally
admonishes the boy, "You're going to go far, Kravitz." This is not meant as a compliment;
MacPherson recognizes Duddy's ability to turn situations to his own advantage and is disgusted by
Duddy's seemingly conscience-less attitude. While MacPherson initially believed that violence
never solved anything, he came to believe that the strong preyed on the weak, and that he was the
victim of unnecessary retribution by Duddy for what he saw as a harmless
remark.