When drummer Lombardo left Slayer in 1992 , the band hired a full @-@ time replacement in Forbidden drummer Paul Bostaph . Bostaph made one mistake out of the nine songs the band trialled him with , on " Angel of Death " . Before the " big double bass part " it is a lead section , which Bostaph could not understand , as he had to learn from live records recorded with Lombardo . Bostaph could not tell how many revolutions the guitar riff goes before the bass sequence . The band members told him it were eight , " perfecting " the song afterwards .