Luke didn't figure out by himself that Marc Wallice was infecting everyone. Someone has to have known and told Luke. I figure "Deep Throat" was someone at Elegant Angel who didn't want to get fired for rocking the boat.

Gene doesn't get any extra credit for beating everyone else by an hour or two. Luke gets credit because had Luke not made such a huge fuss Patrick Collins might not have forced Marc to take an honest HIV test, and Marc might very well have kept infecting more girls. Seriously it was that bad - Luke didn't just report on the outbreak; he (and his "Deep Throat") was the key to stopping it then and not later.