Legal Question in Family Law in California

Yes. Family Courts have much wider latitude in how they take evidence, in part because they are a court of equity, in part because the system has become less and less a traditional adversarial trial-based system and more focused on fact gathering and trying to achieve the best results for the children (with little success, in my opinion, but that's the theory anyway). In addition, when the court is the trier of fact (as opposed to a jury trial) the court can conduct its own inquiry and even appoint its own witnesses in order to get to the facts the court believes it needs to render a decision.

In matters involving the children's best interests, getting all the relevant information for the judge to consider can only help the judge make the best determination. The absolute best outcome will always be the one created by the parents reaching agreements on the custody and visitation plan.