So in the representation to the Grand Jury it was stated that 10 people were killed? Do I have that right?
+/-1 for margin of error.
The grand jury presented on their oaths that 10 people were killed "then and there," with "there" being specified as McClennan County and "then" being specified as May 17, 2015.
We don't know what level of detail that Reyna represented to the grand jury, and it doesn't matter. The indictments are the formal legal instrument. They'll be challenged. The recitation of a tenth person killed ends up being irrelevant in court of law.