Just because a claim can't be disproven doesn't mean it can't be dismissed. If a claim can't be proven to be true, then that's more than enough reason to dismiss it. That doesn't mean you're saying that the claim isn't true. It could be true, but if the claim is unfalsifiable, then there's no way of knowing if the claim is true or untrue, which would make dismissing the claim justified until it becomes falsifiable.