I think I have an explanation for the lack of muzzle flash from his hotel suite. He was firing blindly through the curtains and blinds using his bullet drop and known angle perhaps. Also, there's this:

Keep in mind that there's missing spent brass from the hotel room as well. There's not enough spent brass there to explain all the shooting. A second shooter from a different distance as the video explains would resolve that issue. It also helps resolve the lack of muzzle flash from the hotel suite.

Either way though, we are not being told the full truth of the situation. Heck, just go listen to the official police scanner transcript: