Davis had instructed (.pdf) the jury last year that the recording industry did not have to prove anybody downloaded the songs from Thomas' open Kazaa share folder. Davis read Jury Instruction No. 15 to jurors saying they could find unauthorized distribution -- copyright infringement -- if Thomas was "making copyrighted sound recordings available" over a peer-to-peer network "regardless of whether actual distribution has been shown."

But Davis had second thoughts and, without any urging from the litigants in the case, summoned the parties back to his courtroom in August, writing in a brief order that he may have committed a "manifest error of the law." He heard arguments from both sides and said he would issue a ruling soon.

With Wednesday's opinion, Davis made his revised position official and ordered a retrial -- one with different jury instructions.