There was reporting of multiple shooters in Dallas too, only to find just one that was on the move and the confusion set from all of the echos bouncing off the other buildings.
And this was only proved after a motorcycle mic was found and analyzed.
THIS is precisely why we need to not exclude any other shooters until all things, such as what is to me a clear muzzle flash at the 4th floor (and, no, that’s no strobe) is explained.