Can a plaintiff sustain a false imprisonment claim if he was wrongfully housed in administrative segregation for a period of time?

As to the false imprisonment claim, section 820.4 states: "A public employee is not liable for his act or omission, exercising due care, in the execution or enforcement of any law. Nothing in this section exonerates a public employee from liability for . . . false imprisonment." To state a claim for false imprisonment, a plaintiff must allege he was restrained by another, and that the restraint was completely unlawful and without authority. (See Collins v. County of Los Angeles (1966) 241 Cal.App.2d 451.) As there is no dispute as to whether plaintiff is legally incarcerated, we conclude he cannot sustain a false imprisonment claim, even if he was wrongfully housed in administrative segregation for a period of time.