I think it's worth constructing a different example to illustrate the syntactic principle involved here. Suppose Dudley goes to a small "community-driven" village school with no full-time paid teachers, where both parents of most pupils all put in an hour or two a week teaching at the school. But Dudley's parents don't participate in this teaching...
1: Dudley is a boy whose parents don't teach
2: Dudley is a boy whose parents don't teach him
In #1, teach is an intransitive usage, meaning Dudley's parents don't teach anyone. There's no specific implication from the syntax that they don't teach their own son - that's just a pragmatic assumption given the context.
But we can further imagine that when the village decided to run their own school, they arranged the classes in such a way that no parent ever had to teach a class that included their own children (perhaps to help maintain discipline, for example).
In that scenario, my example #2 wouldn't really make sense (if none of the parents teach their own children, why single out Dudley as an example of this?). But it would make sense if we shift the scenario slightly, to assume that only some parents asked not to be assigned to take classes that included their own children - in which case even though Dudley's parents don't teach their own son, they do take classes with other pupils.
3: He is the man whom she loves
4: He is the man who she loves
5: He is the man [who / whom] she loves him
...where strictly speaking only #3 is "correct" (because pronoun whom represents the man - the "object" of the verb; it's She loves him, not She loves he).
But in practice most native speakers today nearly always who instead of whom (except when preceded by a preposition; even today, many people still observe this fast-declining "rule" in contexts such as asking To whom am I speaking? on the telephone).
Finally, note that example #5 is never valid. Whichever of who / whom you choose, it's a pronoun that represents the man (we don't repeat that reference with him as well).