This week, the highly regarded public radio show This American Life learned a lesson that many journalists, including me, have learned the hard way: It’s almost impossible for an editor to fact-check a contributor who lies.

The show, hosted by Ira Glass, just retracted its Jan. 6, 2012, episode, “Mr. Daisey Goes to the Apple Factory,” adapted from Mike Daisey’s popular one-man show, The Agony and the Ecstasy of Steve Jobs, which is about working conditions in a Chinese factory that makes Apple products.

Daisey’s deceptions were uncovered by Rob Schmitz, a China-based reporter for Marketplace. This American Life will air an hourlong explanation and re-examination this weekend, featuring both Glass and Daisey, about the circumstances behind the retraction. Glass and the show are to be commended for their quick response, and everybody who cares about real journalism owes a debt of gratitude to Schmitz.

We don’t yet know all the lies Daisey told Glass and the listeners of This American Life, but here’s a taste. In the Jan. 6 segment, Daisey said:

The problem is that n-hexane is a potent neurotoxin, and all these people have been exposed. Their hands shake uncontrollably. Most of them can’t even pick up a glass.