Answer:
Fundamental attribution error.
Step-by-step explanation:
In psychology, fundamental attribution error also called attribution effect or correspondence bias is the act of under emphasizing the situational explanations of an individual for the observed behavior of the individual while over emphasizing the personality based explanations for the behavior. It is sometimes described as the belief that people do whatever they want to do and what people do shows who they are.
In both examples mentioned in the question, the boss never gave the affected individual the benefit of doubt and he believed he wasn't saying the right thing.