When is it OK to recover battlefield artifacts then? Roman battles - all good, Napoleonic battles - all good, Boer war - all good. Is there some magic date that switches a site over over from being a memorial to a source of historic relics? I don't think so. There is usually some lawful control over such artifacts and their distribution and possible sale, but I can't remember, isn't the Afghan government slightly tied up at the moment? Clearly interfering with interred remains or even un-interred remains is something that shouldn't happen (don't mention this to the local wildlife though), but I suspect the first time this location came up on anyone's radar was 140 years after the event.
The sheer irony of what was once a great newspaper (before it became a salacious rag) printing an article about looting battle sites in far flung corners of the globe is obviously lost on the so-called journalist, who clearly has never visited any museum in London. Classic muck raking from a very old **** pile.