MILWAUKEE, WFor reasons unknown at press time, Milwaukee resident Keith Randall purchased the DVD of the 1997 Keanu Reeves-Al Pacino film The Devil's Advocate Monday. Randall, 31, reportedly entered a Blockbuster video store and handed a clerk $21.99 in exchange for the film. 'I can't claim to know what he was thinking,' said Blockbuster employee Gary Nathan, who sold Randall the DVD, which contains 22 minutes of bonus footage and an exclusive interview with Devil's Advocate director Taylor Hackford. 'I'm baffled. I could see maybe watching it once on HBO, but this?' 