Greenlights, you are quite astonishingly stupid. The pilots don't push the aircraft back, the ground crew do. They have control and they're the ones who can see what's happening around them. As for the taxying a/c, they would almost certainly have had clearance all the way on to stand and expect the aircraft waiting for push to hold until they were cler, as per the likely ATC clearance.
Now, it is POSSIBLE that ATC didn't issue a conditional clearance to the pusher, orr that the pilots failed to pass that on correctly to the ground crew, or the ground crew may have not understood it correctly. That is what the investigation will find out and has yet to be released, but they are trigger factors, not causal - the causal factor is the ground crew pushing an aircraft infront of a taxying one. So, Greenlights, you owe the pilots an apology.