The character doesn't seem to be integral to the story line. This character seems to only serve the purpose of being an obscene place marker.
I haven't read the book, but the only thing I can possibly come up with is that Webb was trying to stress the point that people surrounded by war become numb to even the most abhorrent sights among them. If that was what he was trying to point out and that's what he believes, then I think it says a lot about Webb as a person. Decent people do not lose their decency in war even if there are some things that are out of their control. No decent man is going to watch a scene like this and treat it non-chalantly no matter how many horrors of war he has been subjected to.
I've never been to war, so I can't say whether or not this is accurate. Have you been to war?
As I noted in my previous message, Allen is in trouble if the issue mutates in that direction....