Did you prepare the application yourself or have a lawyer do it?
In the Probate application, it requires that the executor include the assets and liabilities as at the date of death. It is critical that all assets are included as asset holders will need to sight the Grant of Probate for the executor to deal with the asset (eg, real estate). However, the liabilities are paid out of the estate anyway
before the assets are distributed, so its not the end of the world that the credit card debt was not included, as long as its paid as a priority.
IF you need more information, you can read
Probate - Legal Documents - LawAnswers.com.au