Killer Ground ‘Bots Out of Iraq: How Come?

To great fanfare last year, the Army deployed three machine gun-armed Sword ground robots to Iraq, promising they would see combat "soon." But just a few months later, the Swords were sent packing. How come? Popular Mechanics knows why:

[T]he Army’s Program Executive
Officer for Ground Forces, Kevin Fahey, was asked what happened to
SWORDS. After all, no specific reason for the 11th-hour withdrawal ever came from the military or its contractors at Foster-Miller. Fahey’s answer was vague, but he confirmed that the robots never opened fire when they weren’t supposed to. His understanding is that “the gun started moving when it was not intended to move.” In other words, the SWORDS swung around in the wrong direction, and the plug got pulled fast. No humans were hurt, but as
Fahey pointed out, “once you’ve done something that’s really bad, it can take 10 or 20 years to try it again.”