I hate being tired, but I'll try to see if I can help any...
I can hardly seem to remember most of the rules at the moment... But one thing I know for sure you could do, is place a maneuver on them, and tag it for effect. From their, the ST could compel the said person to be disarmed, but at that same point, the NPC could say no, and spend a Fate Point.
But if I recall, hazy as it is, that isn't the only way to go about it. Again though, I really wish I could help more... I shouldn't respond to posts when i'm about to pass out >.<