that she mistakenly pulled her service revolver instead of her taser.
A. The service revolver is a Glock 9mm and is to be worn on one hip, while the taser is to be worn on the opposite hip.
B. Any damn fool who has ever touched one knows that there is a difference in heft between a Glock and a taser and can tell the difference in less than the time it takes to yell "Taser, taser, taser!"

She fcuked up, pure and simple. Either she was wearing them on the wrong sides or knew she picked up the wrong one and fired anyway.