WSJ:
In the two days since, however, a new fact came to light that muddies her explanation: [the runner] herself isn’t sure she ate the pork burrito in question.
[The runner]’s lawyer...confirmed in a Wednesday interview something first reported by the website LetsRun: that [the runner] actually ordered a carne asada burrito, not pork, the day before her drug test. They believe [the runner]was either given the wrong order or a burrito that included pork, [her lawyer] said. They don’t know for sure.
[The runner]’s initial statement didn’t mention that she ordered a carne asada, or beef, burrito, not pork. In the interview, her lawyer said the order was beside the point because the anti-doping lab’s analysis wasn’t done correctly.
Meanwhile, she "will be allowed to run at the U.S. Olympic track and field trials while any appeals she files are pending."