I agree. If this was an international race, I think there would have been a French protest and possibly a DQ. If this was the NOP, there might have been a protest and a DQ.
I really think the poster below nails it perfectly.
There was zero reason for Kipchirchir to be coming down on hill. It was the final turn of the race. There would be no other turns so no need to come down into lane one when he didn't have clear separation. In horse racing, a move like that could get you DQd.
But my main thought is the officially generally almost never are going to allow someone to extend their arms and shove them. I guess Hill could say he was trying to prevent a fall for both of them but if this was an international race, I think most people are instinctively going to see someone's arm fully extended on the back of another runner and instantly DQ the person doing the shove.