Where do you get "erroneously"? What I heard was that the Grand Jury said the officers had a warrant and a right to be there and returned fire.
The original premise for issuing the no-knock warrant was the suggestion that a suspect in a drug investigation was receiving packages at Taylor’s house. In the warrant filing, the police claimed this was verified by the US Postal Inspector in Louisville. The Louisville Postal Inspector said the police account was wrong, and that no packages of interest were ever received at Taylor’s house.