Jockeys move out of the way for Borel??

I am listening to AM sports radio this morning, 980 WTEM in Washington and thye've got some horse guy saying that Borel made that trip. So John Thompson aks him "He was in 19th place, how do you make a trip."

SO the guy says that when Borel moves up he starts shouting "Coming through" or some such and the jocks move out of the way.

So Thompson says "Let me get this straight, I am on a horse in front of you and you are behind me and you yell at me and I move over?"

So he says well some of these horses are tiring and the jocks know that they cant win so it's some sort of courtesy and tiring horses come off the rail, bla bla bla.

So now I dunno what to think. Do they come off the rail because they are tired or because Borel tells them to move off? Or both?