Remus was so shocked at seeing Sirius fall through the veil that Harry had raced past him before the boy’s intentions even registered with the werewolf. Screaming “Sirius!” Harry followed his godfather into the veil before anyone could stop him.
What will happen when a goblin-raised Harry arrives at Hogwarts. A Harry who has received training, already knows the prophecy and has no scar. With the backing of the goblin nation and Hogwarts herself.