No surprise at all you would have these guys shooting prisoners.
In short, we don't need to see the orders to know what was going on.
Certainly there were atrocities against Boer civilians that largely went unpunished, and very often unremarked.
But in this case, the issue did primarily revolve around Boers who were under arms - which is, in fact, why they were entitled to the protection of Prisoner of War status. If they had just been civilians shot down in cold blood, it’s less likely anything would have happened at all.
Britain was not ‘actively’ engaged in genocide against the Boers, that is a myth.
The deaths in the Boer camps were appalling, but not deliberate. The deaths in the camps came about because the Boer community over the decades had not intermarried with the other European groups, and as a result had no or little natural genetic resistance to certain disease such as typhus. A fatal mix of passing genetic flaws constantly within the community and no ability to ‘bring in’ other European genetic strands which would have helped the Boer genes.
Hence the women and children and old people had no resistance to the rampant disease, not helped by the unintentional but appalling mismanagement of the military.
There was a public and political outcry in Britain and Ireland when the nature and the horror of the camps became apparent, and that almost overnight massive changes were made, including hundreds of doctors and nurses being sent along with many supplies to South Africa, the running of the camps being civilian not military and after the changes the rampant diseases stopped and deaths ceased.