Maybe he passed them at the same spot where he said "down the hill"...got on the bridge as to walk across then turned around and started walking back?
I got to thinking... why leave it in? Maybe they distorted it just enough to not be blatantly obvious that is what it is, but didn't delete it...
I hear it with earphones on. I tried to unhear it or not hear it. It would explain why they separated the audio. JMO
He is definately pulling something, at least his hand, out of his pocket. It almost looks like he is wearing something on his back that sticks...
Gray Hughes has a video with a loop of the audio.
I hear "Let us go, or let go" drawn out scream. I can't unhear it.
Out of curiosity... how would knowing this help the investigation?