In Enzo's CBS Biography, Enzo said that the past houseguest he liked the most was Justin from Big Brother 1, even though there wasn't a houseguest named Justin on Big Brother 1.
Enzo likely meant Justin Sebik from Big Brother 2.
Justin was expelled from the house on Day 10 for holding a knife to Krista Stegall's neck and threatening the other houseguests. As an expelled houseguest, he was not invited back to participate in the final vote.