"Attorney General Daniel Cameron said his investigation determined that Jonathan Mattingly and Myles Cosgrove were justified in their actions and that they did announce themselves as police officers before the shooting."
How the warrant was issued is irrelevant at that point
https://www.usatoday.com/story/news/nation/2020/09/23/breonna-taylor-announcement-grand-jury-louisville-police-case-updates/5814876002/