The accounting fraud case against former McKesson HBOC executives has taken on an “Alice in Wonderland” hue, as the government’s main cooperator is now officially a defense witness.

In opening statements Tuesday, Theodore Wells Jr., the Paul, Weiss, Rifkind, Wharton & Garrison lawyer representing former CEO Charles McCall, told the jury he will call Albert Bergonzi to the stand. Once the company’s president, Bergonzi pleaded guilty and testified for the government in its first attempt to convict McCall and former General Counsel Jay Lapine. That jury acquitted McCall and Lapine in 2006 on one count, and hung on several others.