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.
If they’d been shooting women and children they’d gotten a Victoria Medal.