I've been paid in error, how can I owe CSUSB more than the net amount I received on my warrant (or in my bank account)?

When a warrant is issued, federal and state income taxes are withheld and forwarded to the Internal Revenue Service, Franchise Tax Board, Medicare and Social Security on the employee's behalf. Miscellaneous deductions, such as garnishments and deferred compensation (TSAs/403Bs, etc.), may also be withheld and forwarded on the employee's behalf.

So, if an employee is paid in error and the State Controller's Office is unable to recoup the deductions forwarded on their behalf then, the employee will owe the net amount plus any deductions taken from that warrant.