Battle of Palmetto Ranch, 1865, why so few deaths?

[His lordship.]

At Camp Mabry's military museum in Austin, TX there is a display (diorama) of the last good sized battle of the Civil War, called Palmetto Ranch that happened in May 1865.  What is weird is that there were only 4 killed and 5-6 wounded.  These two forces shot at each other for 2 days with the later war percussion rifled muskets, and that is all that got hit??
 
It seems odd that they could not shoot each other.  At the First Bull Run battle in 1861 the casulties were low, but they were using alot of the older 1842 smoothbores and even older designs.  If you put hundreds of soldiers up in front of me and I had an 1863 Springfield, I am certain I would hit someone with several shots.  The terrain was open and more desert like in South Texas, so obstacles were not an issue.  Does anyone know further on why this battle had so few killed/wounded?
 
Thanks.

[reliquary]

According to Shelby Foote, volume 3 of his Civil War narrative, the Union forces lost 115 killed, wounded and missing, but doesn't give the Confederate casualties.
 
I do know, from Foote's books and other reading, that most soldiers on both sides had lost heart and were just waiting for the remaining gray soldiers to surrender. Everyone knew Lee had surrendered. The only Confederate general in the Texas-Louisiana region who wanted to continue the war was Jo Shelby.
 
 Kirby Smith was in nominal command of the Confederates, but didn't want to fight, and was at odds with Shelby, who wound up going into Mexico with the diehards...to no real avail. 
 
No one wants to be the last one killed.

[His lordship.]

Thanks for the info, some other material I had read on this did mention there were other figures for casualties, some supposedly drowned in the river.  Also, there was a gentlemen's agreement between the opposing commanders for awhile to just live and let live.  I can see the point in not wanting to get shot when the war was clearly over, but there are a few hardcore cases in every war, revenge, bloodlust, etc.
 
Still it seems hard to believe more were not hurt with hundreds of gun barrels shooting in one's general direction for 2 days.  I wonder if there was alot of staring and yelling at each other instead?

[subdjoe]

There are a couple of things things.  First is that early in 1865 there was a sort of general agreement that to carry on fighting was kind of pointless.  Rejected by the theater commanders, but pretty much everyone below them thought it a good idea. 

Then, there really weren't all that many troops involved. Total of 800 or 900 combined.  Spread 'em out over even a few hundred acres and there aren't many bunched targets.

[reliquary]

Good points, all.
 
After re-reading Foote, his account of casualties was ambiguously worded, and may well have included the Rebs, too.  It was the total of all "killed, wounded, and missing".  No spread on the subcategories.
 
Local accounts of the last weeks of the war, from relatives and families in East Texas, plus formal research in Virginia, shows a lot of those "gentlemens' agreements." 
 
There's a well documented local account of soldiers from both sides "just takin' off their gear and walkin' away in the direction of home"...metal-detector enthusiasts have found some uniform and harness debris in the area. 
 
Foote shows three Union regiments and a Texas source shows two Rebel regiments.  By that time in the war, no one was up to full strength.