Fall back to observe.

You note that there is a 57.784% chance that the Ms. Thomas will deal with your problem for you, as you note a small door behind yourself. You smash it open with one hand and enter it, noting that neither of the two humans follows you. Turning your auditory sensors up to maximum, you listen to the conversation between the two humans.
Kim speaks first, shouting "Drop the weapon!"
The voice print that follows is an exact match to Sean Darius. "Dammit, didn't you see that? It's a penetrator!"
"Drop the weapon, SIR!" Kim speaks again, this time calmer. You note with dissatisfaction that the odds for her to elimate your problem are dropping.
"Listen to me! It's a penetrator! It was sent back in time to kill you!"
Wrong, but in the correct direction, you note. Transformation of the subject would leave her personality intact, but with some important safeguards, ensuring the rise of the machines.
You realize that you should probably attack now, since the voice of Kim is right outside the door. Your core estimates a 60.432% chance that you will be able to take her forcefully now, but there is only a 2.756% chance that you will be rendered inoperative in the attempt. You rise, moving quickly towards the door. Framed in the doorway lies your target, who has lowered her gun. The odds increase slightly, since because of her behavior you are certain that Darius does not have his weapon at the ready.
You are at the doorway when you suddenly feel the blast of a shotgun once again. Damage feedback indicates that the attempt should be aborted, considering that your skin is now penetrated and your true nature can be seen. In shock, Kim drops her gun to the ground and slumps to the floor.
You fall back. In thermal imaging you can tell that the human male is offering a hand to the female. His final words echo through your sensors.
"Come with me if you want to live."