Every single person yelling at Arashiyama to hurl him out of the ring doesn't understand judo/grappling, and probably don't even lift. You need a huge amount of leverage and strength to toss a heavy weight several feet out of a ring and not just to the ground, to say nothing of an uncooperative man your own size. The open platform makes ring-outs by momentum possible (similar to Gaolang's DQ), but Hayami is too fast for that to work.
Personally, I think Arashiyama's strategy at this point should be to keep trying to break his opponent's fingers, limbs and possibly his lower spine, a la Bane. Even with a congenital insensitivity to pain, mechanical damage can't be overcome, thus completely disabling an opponent should result in victory by TKO.