Here is the pertinent language of the statute at issue:
Harassment, alarm or distress.
(1)A person is guilty of an offence if he—
(a)uses threatening, abusive or insulting words or behaviour, or disorderly behaviour, or
(b)displays any writing, sign or other visible representation which is threatening, abusive or insulting,
within the hearing or sight of a person likely to be caused harassment, alarm or distress thereby.
Thus, “a person is guilty … if he….. uses … insulting words… within the hearing …. of a person likely to be caused …. distress therby.”
Can you imagine trying to enforce such a statute at a Yankees’ game? Or a political convention?