He's the one who took the blame for the mine's horrific safety record, claiming that he'd felt pressure to perform by the mine's noblepony owner, Lord Galloway Bitsmount, and had undertaken cuts to timber expenses on his own initiative. Cuts which had led to an unsafe mine, with collapses and injuries at a rate far and away higher than any other mine in Equestria. It was almost three weeks ago that Artemis’ VIP initiated an investigation and brought charges against Lord Bitsmount, though with all that had happened since then it might as well have been three years ago. And now Princess Celestia had sent the confessed delinquent to serve the Royal Engineer as an assistant!