Let's see... first arrow in the shoulder.
2nd arrow, more in the chest.
3rd arrow, in the stomach area.
I will admit it is not clear...
No one comes near him with a sword between the shot of it not broken and the shot of it broken.
But, you have to admit... that is one great fight scene.
The second arrow went low, creasing the pancrease, the traversing segmet of the lower intestine, and probably nicked the kidney...
the third arrow hit between the two, taking the lower lung and possibly the renal artery... and didn't strike anywhere near the horn...
he would have bled out more quickly (30 seconds, max), if he'd been hit with broadheads... everyone, including Legolas, is using bodkin tipped arrows, for punching through heavy armor...
My daughter and I thought the same thing. We knew no one had hit it with a sword, so we think the arrow did it. At the velocity at which it was coming from the crossbow, I think it could cut the horn in half!