In case you missed it, Andy Pettitte took the stand on Wednesday for the second time to testify in the perjury case against his old friend and teammate Roger Clemens. Pettitte's presence was considered key to the prosecution, but the testimony ended up offering them little support. Pettitte confirmed assertions that he was uncertain — "50-50" — about whether Clemens had admitted to using human growth hormone to him back in 1999 or 2000. Local papers and major news outlets have seized Pettitte's ambivalence as the potential downfall of the case against Clemens, even coloring the story with a bit of fishiness. You've probably heard it suggested that Pettitte "flip-flopped" and that the timely change of story might single-handedly sink the prosecution. Look a little deeper, though, and that doesn't appear to be the case.
Craig Calcaterra of Hardball Talk actually went back and looked at Pettitte's original testimony to Congress in 2008 and determined that, in fact, Pettitte's present words don't really differ at all from what he had said previously. Tamar Chalker of It's About The Money, another former lawyer/law expert, looked back as well and agreed, and you can take a look yourself (the links are all there).
The upshot is that Pettitte hasn't really "flip-flopped" at all, and he doesn't appear to be doing anything questionable to "help his pal" or whatever. The fact that there's been an uproar over Pettitte's testimony seems to suggest that: (1) perhaps the prosecution shouldn't have expected to lean so hard on his testimony, and (2) news outlets making a huge deal out of Pettitte's testimony are being misleading, because (3) if Clemens is found innocent, it's not going to be because of what Pettitte did or didn't say. If you're interested, though, have a look at the 2008 testimony and decide for yourself.