Read this a few times, and then return to the rest my comment...
... execution of wounded prisoners did not even warrant a whole sentence. That’s literally all Tolstoy wrote about it.
I don’t think he was callous, I think at the time it was the norm and didn’t warrant a mention except in this case the unpleasant task was delaying the transport.
^ citing from memory
^^ this is the Napoleonic war of 1812. At least 100 years later the brutality deserved mention.