CBP employees get sued?
Ain't gonna happen.
As a former fed, I can assure you that a federal employee acting in an official capacity will never face a personal suit. The reason is that the fed steps in as the defendant in place of the employee. That's part 1.
Part 2: in the United States, the federal government has sovereign immunity and may not be sued unless it has waived its immunity or consented to be sued. This doesn't happen because it exposes the government to liability.
Now, the employee who screwed up will definitely have a bad day for causing problems, but will probably not be fired.
The only ways for a fed to be fired are to commit time card fraud, steal equipment, or perform sexual harassment. Practically speaking a fed would need to be caught with a live boy or dead girl to be removed on the spot.
Security violations may get you there, but with the precedent set by Hillary and her staff, who the heck knows...