ROs have to meet legal standards, which differ by state. Typically though these standards are existing laws that fall under stalking and harassment laws. In other words, a RO should not be granted unless the plaintiff can show a law was broken- being mean, rude, swearing, talking to friends, etc is not breaking the law and thus not grounds for a RO.
That said, the weight is put on the defendant. Typically a judge won't bother to read or analyze the RO petition, they'll just grant it.
Anyone who is hit with an RO should, if not already granted, ask the court to not issue the RO until a hearing.
In either event, a hearing must be requested.
Then, the defendant can go point by point on the petition/complaint and show that each item does not meet the legal requirement.
Arguing that it's all lies is a different matter. The defendant would issue to the plaintiff an Order for Discovery asking for all documents, diaries, notes, phone records, etc. that "prove" their point. This would be done before the hearing.
If the defendant can show that the petition does not meet legal requirements, or that the "proof" is immaterial or insufficient, then the judge should toss out the petition.
In most cases the laws upon which TRs are based (e.g., "harassment") use the word "intended" (e.g., "intended to cause emotional trauma") and it's hard to prove intent.
Fact is, 90% of TROs should never be granted. But they are.