He was not “running blindly”, he was walking after he quickly ran out of gas and people were directing him to the shooter. In an area such as an outdoor mall I am certain it can be difficult to pinpoint the direction the shots were coming from but you can also see blurred out images as he moved forward and I have to assume those were victims. So he knew he was getting close. He did manage to control his breathing enough when he fired his weapon.
He certainly wasn’t running blindly - my point is that slowing down as you get closer to the sound of the gunfire is a good idea, so you don’t get unpleasantly surprised. As opposed to running straight in at full speed as some would want.