Actually that’s exactly what they are saying he was doing - running between windows because each window offered a different field of fire.
Trouble with that theory is that you’re dealing with an overweight, out-of-shape sixty-three year old guy with a history that includes a fall in a casino which required medical treatment.
Someone wants you to believe that *this* guy ran between those windows and fired hundreds of rounds through bump-stock modified rifles for eleven minutes. And then shot himself.
did he have both the guns on some sort of tripod?