Plot hole: Nick Fury wants to detain Tony as he is the only witness. Tony takes off and Nick Fury even says to apprehend him so their only witness isn't killed. Yet when the S.H.I.E.L.D. robots confront Tony at Pepper's vacation spot, they say they are authorized to use deadly force against Tony. And Nick Fury even orders them to fire when Tony resists. If they need Tony to keep their only witness alive, why try to kill him when he doesn't cooperate?