Such an odd phrase

Consider this: On page 136 of Bleeding Edge, the author(s?) describe a TV character, Hakeem, as a “pro defensive linebacker,” which is a silly phrase since all linebackers are defensive -- an indication that the author(s?) don't know football. That's particularly interesting when he(they?) do such meticulous research into the dot-com era and Russian hip-hop history in the same chapter. So why didn't the commentators at tabloidofthedamned.com catch this error? Could it be that they didn't realize it because they're the ones who committed it?