Perhaps his holiday time had been miscalculated due to a glitch in the system.
I worked in the computer lab, and as a lark, I wrote a cute program where an inmate could input their projected release date, and the program would tell them how many tacos they had left before their release.
Years later, after my release, I learned that the department of corrections had been sued by an inmate who alleged their "Taco Time Calculator" had miscalculated his sentence.