So heh i was actually recording this bit when i noticed the thing about Lewis and the spike.

What I was wanting to point out if that Lewis was facing Arthur AS he was pushed. He wasnt pushed from behind. He had, for some reason, turned around to face Arthur. If he was pushed from behind he would still be facing that way in this shot and could have turned around as he fell. But hes already turned around at the top of the cliff.

So what made Lewis turn around? Maybe Arthur did manage to make a sound or some attempt to get help/warn Lewis. So if Lewis turned to check on Arthur, his last words might have been something like “ Are you ok Arthur?”