I agree that PSIOs can and are weaponised. Have a case atm whereby someone was removed from the workplace because of a PSIO (unusual circumstances I can't elaborate on). Others are retaliatory, others clearly not warranted, yet people are being breached every week in Vic.
We can help if your friend wants legal assistance. There are a couple of ways forward and police/prosecution will often discuss the matter with a lawyer in way they will not with a respondent. Most times they simply say to a respondent "tell it the court".
We can assist with both the PSIO and defamation.