John McTiernan.

An attorney for the Die Hard director was vowing an appeal after the filmmaker was sentenced Monday to four months in prison for lying to an FBI agent investigating Hollywood private investigator Anthony Pellicano.

In April 2006, McTiernan pleaded guilty to a felony charge of, essentially, telling an FBI agent that he'd only used Pellicano's services during a divorce, only to later admit he'd also called on the detective to wiretap the office of producer Charles Roven, with whom he made 2002's Rollerball.