> Again, why would the security guards not trust the judgment of an employee of the company that hired them?

This would be a stupid thing to do, even at the office. They could listen maybe the director of physical security, etc, but not a random employee. Especially for a company of Salesforce's size.

If a random employee told them the badges are ok, they should've deferred to someone who can make the decision. Either a) the employee's right and the badges are ok, or b) the employee's trying to trick security and should be reported to the company. They did not have to make a final decision on the spot.

Maybe they should have done (b), sure. Otherwise, the badges are not ok for security, and a random employee telling them anything doesn't change status quo.