This not really my field and hadn't really dealt with the Protection from Harassment Act. But based on my recollection, the purpose of the Act is not to deal with minor annoyances but fairly serious conduct. E.g. online doxxing is an example given in the Act, whereby Person X reveals personal information of another Person Y intending for the community to harass Person Y (see illustration (c) of the screenshot).

So it depends on how the argument escalated and what he did in response to that argument.