When faced with a Probate Court Petition that you do not agree with, you must object. Luckily, in California you have some leeway on when you can object because our Probate Code allows interested parties to object orally at the initial hearing. In other words, you technically do not have to have a written objection before the initial hearing date.
But that does not mean that objecting orally is the best way to go. In most cases, we prefer to file a written objection at least five days before the hearing date to ensure that the objections are preserved.
Probate court is a court of equity—meaning the court can take action, issue orders, and approve petitions anytime there are no objections. Even when there are objections the court can overrule the objections and issue orders—although the law requires a trial at which to present evidence to decide most probate court matters.
The point is that if you fail to object in writing, and if you fail to show up on time at the probate court hearing, then you may be out of luck. Once the court issues orders or approves a petition, it takes a good deal of work to overturn the result—assuming you can overturn it at all.
If you are going to rely on an oral objection at a probate court hearing, then be sure to show up on time. If you want to play it safe, then file your written objection well before the hearing date so the judge will be sure to read it.