This is an entry for Finish the Story Contest - Week #66.
Here is 
"Don't state the obvious," the human Colonel warned the iron sentinel.
"But I don't remember," a deep metallic din protested. Though called iron sentinels, these were state-of-the-art humanoids made of titanium-mercury alloy. They could withstand the blast of a thousand RDX and come out without a scratch.
"What was that?" Colonel Arlong had never witnessed a sentinel raise its voice, least of all, protest. A forty-ton humanoid towering fifteen feet over the Colonel in a dim-lit interrogation room was definitely not a foe that the Colonel expected to antagonise.
"Sorry, sir. I didn't mean to.."
"You didn't mean to what?" Arlong ensured that he maintained an upper-hand. The sentinels were smart AI and could sense human emotions from miles. If they ever sensed fear, then only the Almighty would have to intervene to save the human bosses from the sentinel's wrath. After all, these were created to exterminate humans; the enemies of the bosses.
The sentinel's blue lights, substituting for eyes, stayed focused on the colonel. They didn't blink. They never did. "I was about to fire, but the screams of the younger human brought back some memories."
"Memories? You have no memories. You have no consciousness. None of the sentinels have. All that you are made up of is a clock, gears and Radium-powered cells."
"I don't know. I was unable to open fire. It felt like my son," the C-10Z01 looked away. That was another unusual expression. Machines don't look away, and they don't have children.
"Alright, this has gone too far. We need to investigate your synapse," the Colonel got up, and so did the sentinel, "and you will not resist the link."
"What will happen?"
"That's none of your look-out C-10Z01," the Colonel was curt. "Take him out."
Two more sentinels walked in and grabbed C-10Z01. The machines walked out with loud dins and thuds following their moves.
The Colonel lit his cigar, and even before he exhaled, words poured out, "what did we just witness?"
"I don't know, sir," Jennifer, the resident sentinel architect, responded.
And this is my ending:
Colonel Arlong turned on her. "I don't know doesn't cut it. I'm asking my brigade's architect, not quizzing a schoolgirl on arithmetics."
Architect Jennifer, PhDs in mathematics and computer science, bit her lip. "Apologies, sir. I have no conclusive answer, but I can hazard conjectures for you."
The Colonel approved. "Better. Come with me."
They exited the interrogation room and made for the elevator. Along the way, soldiers stationed in the corridor saluted their commanding officers.
"...programmed for a specialized function," continued Jennifer, "that being anti-personnel and vehicle combat. Unlike full AIs, they don't need higher cognition. Their software focuses on sensor data analysis and tactical reactions."
Arlong drew on his cigar. "That unit claimed it had memories. It ignored a direct order."
Jennifer shook her head. "And that's baffling. Not enough RAM for complex recordings. The term 'son' isn't in the standard vocabulary. Developing a conscience, understanding social concepts... Theoretically, miraculously, it's possible, but given their computing power, processing would require... time."
"How long?"
Jennifer paused for a quick calculation. "...centuries. Millennia. But the war's only begun--"
"Don't state the obvious," the Colonel cut her short.
They had arrived at his office. Arlong ushered them in.
"Which leads to the possibility of outside tampering."
The architect gasped. "Sir, you think the enemy--"
Arlong sat at his desk. "We're winning. They're desperate. And they've always been cunning. What if they found a way to induce human weakness--hesitation, doubt, remorse... rebellion!--directly inside our weapons? What if it's viral?"
Opening a side drawer, the Colonel pulled out a large metal case. When she saw the switch, Jennifer knew instantly what the contraption was, and what that meant.
"Sir, if I may--"
"You may."
"A brigade-level hard reset to factory settings... It would erase our sentinels' accumulated combat experience, reducing their effectiveness."
"It will also ensure they shoot when commanded. At the correct targets."
"If we could wait for the synapse analysis--"
"Just like iron sentinels sense fear from miles away, a career Colonel can sniff a mutiny from before it happens." He smiled bitterly. "Architect... You might think highly of your AIs' efficiency, but there are reasons why military protocols put humans in charge of making decisions. Experience. Instinct. Wisdom. Resolve. That's what makes an army ultimately work."
Jennifer knew when she had to snap to attention. "Yessir. Thank you, sir."
Arlong nodded gravely. "First rule for winning a war: don't lose the war."
He pulled the switch.
The lights went out.
The lights turned back on.
A relaxed Colonel Arlong slid a new cigar in his breast pocket. "So. What's next in my schedule?"
Architect Jennifer blinked twice, slowly, then hurriedly looked down at her files. "Something for you, sir. Unit C-10Z01 malfunctioned this morning, it refused to fire. Here's the report."
The Colonel opened the folder and skimmed its contents. "I don't like the looks of this. Take the unit to the interrogation room." He sighed. "It's going to be a long day."
