He does not have to be exactingly precise in the arrest warrant because the exact position of the sheath as opposed to the general location of near Maddie's body in the bed is not relevant to the arrest warrant. The fact that a knife sheath was recovered from the bed in close vicinity of Maddie's body IS relevant, and the most relevant thing is that the sheath in that proximity to the body was found to have DNA on it. The arrest warrant and the search warrant are not police reports nor are they forensic tech reports. They are summaries. If a knife sheath is half under her and half sticking out to the side of her, then for simplicity's sake some people are summarizing that by describing the part they see sticking out next to her as simply "next to." They don't have to put in details that are unnecessary for the purposes of the warrant. Heck, neither the arrest warrant nor the search warrant even mention where Ethan's body was found other than "Also in the room was a male, later identified as Ethan Chapin, hereafter, "Chapin". "
The point you would need to worry about is if the Prosecution has the information wrong. And from their June 16 State Motion for Protective Order, it is clear that the Prosecution has exact and correct information.
"The sheath was face down and partially under both Madison’s body and the comforter on the bed."
And the Defense has the forensics reports and the actual police reports from the crime scene processing that day. And if that information on there wasn't exact and correct, we would have seen the Defense filing motions about it by now. And they have DEFINITELY gone through the immediate crime scene reports by now, even if they haven't made their way through all the tons of other stuff.