Where does your information come from?
Neighbors agree that police didn't announce. LPD used a battering ram on Taylor's door, which isn't usually associated with knock & announce.
Either way, Kenneth Walker was licensed to carry his firearm, had no criminal record & was not found to be in possession of narcotics, so what possible motive could he have for knowingly firing at police?
How do you figure Taylor was "central" to the investigation? From what I understand, police alleged that packages for Jamarcus Glover, who was the focus of the investigation, had been delivered to her address. That, & her friendship with Glover, were cited as the central features of the warrant.
On what basis do you contend that the raids were simultaneous? Accounts I've seen claim Glover, who lived miles away, was definitely already in custody well before officers entered Taylor's home.