EUGENE, Ore. (AP) — Were it not for Shelby Houlihan and her head-scratching case involving a pork burrito, the talk of doping might very well be Brianna McNeal. Like Houlihan, McNeal, the defending Olympic champion in the 100-meter hurdles, has been hit with a ban that places her future in jeopardy. Like Houlihan, McNeal’s case has wound through the international drug-testing organization and made its way to the the supreme court for sports. Unlike Houlihan, McNeal had a place on the starting line at the Olympic trials Saturday even though she has been found guilty of a doping-rules violation. What the cases have in common is true of so many doping cases: They are intricate, confusing and often portray the entire system as rigged or, in the worst telling of it, corrupt.