The only account that i have seen which even mentions an officer is Bevier's "History of the First and Second Missouri Confederate Brigades, 1861-1865." He notes it was not the officer who did the shooting but was directing the Federal sharpshooter(s) targeting the camel. Six Confederate sharpshooters targeted the officer who was hit. Bevier notes "the man was a Major of an Iowa Regiment. I refused to hear his name, and was rejoiced to learn that he had been severely wounded, but was convalescent." He gives a lot of detail to the episode but leaves even more out. Like the officer's name and unit, what day it happened, who his own sharpshooters were...
I've never bought fully into the Bevier account. He said Douglas was grazing behind his regiment (5th Missouri) when he was hit. Yet the camel was the mascot of the 43rd Mississippi which was not only in a different brigade, it was in another division. Honestly, would you graze your camel behind a bunch of hungry guys you don't know?
Two soldiers of the 43rd MS wrote to Confederate Veteran about the shooting; one said he was killed by a minie ball, the other said it was a skirmisher.
I am more inclined to believe (though I don't have a shred of evidence) that the starving men shot and ate the critter and then blamed it on the enemy. I once had a camel "burger" in the U.A.E. and it was pretty tasty.
On another note, I had a nice discussion with Doug Baum of teh Texas Camel Corps who regularly performs Old Douglas programs here in Corinth. (He will be here with two of his camels on September 30). Doug does not believe Douglas was from the U.S. Army Camel Corps as there is no connection between the officers of the unit and the camel program. He did find an article in a Mobile newspaper from 1860 announcing the arrival of a ship with camels for sale, perfectly suited for work on plantations.