I’m not going to suggest that going to NCAT always requires a lawyer, but one needs to be careful when filing claims (in any court).
There is no one in the court scrutinising the claims, so mistakes like this case do occur.
The courts also want to know that a person is not acting off their own bat (rogues), but with the approval of the OC.
If unsure, ask a lawyer. It’s probably a few hundred dollars worth spending. You don’t have to engage the lawyer to represent you.