The Vault Manager was the manager of a warehouse in Vancouver.
The manager greeted a disguised Sydney and Vaughn inside his building and escorted them down to the vault of the warehouse, where they prepared to download the data from the CPUs. As the manager began to walk away, he noticed a trail of blood on the floor and that the security guard was nowhere to be found. Lauren showed up from behind and tossed a gun at the manager, telling him if he didn't shoot the two agents when they got outside the door, she'd kill him.
As Sydney and Vaughn returned, the manager begged Lauren not to do it, but she ignored him and he erratically fired off a few rounds. Lauren broke her word and killed the manager anyways, shooting him in the ribs.