Def agree owner should be included in the dispute as it’s his / her house.
If it’s an adjudication hearing their is allowance on the form for more than one respondent to be included. Maybe whoever lodged the claim didn’t know (it’s as simple as that).
The number of people living in strata who understand even the basic rules is few and far between. That is why this forum is so good you can get real down to earth answers (rather than legal speak).