Prosecutors encountered a possible setback Wednesday in the Roger Clemens perjury trial.
While under cross examination by defense attorneys, former Yankees pitcher Andy Pettitte admitted there's a possibility he may have misunderstood Clemens during a conversation the two had about human growth hormones.
He had previously testified that Clemens once admitted to using the drugs, but the defense got him to say there was a 50/50 chance he got it wrong.
Clemens famously told Congress in 2008 that Pettitte "misremembers" the history about Clemens' HGH use.
Clemens is on trial for allegedly lying to Congress about using the performance enhancing drug.