Using homo as a derogatory term for a gay man may in fact be totally legal, if morally foul. But calling a father a pervert who has interest in his children is the real defamation here, and the real point of what this idiot was saying.
As long as it is true that this father never abused his kids, then it’s kind of a slam dunk defamation suit. You can’t just go around calling people perverts towards children, those kind of accusations do serious harm to social lives and job prospects.