Optimus ordered the Autobots to stand down.
The Autobots knew their leader. When he said 'stand down', there were three kinds of orders that could mean.
The first meant there was new information that they might not be aware of, and the situation had changed. A prolonged battle was either unnecessary or wrong. It could just be a misunderstanding. Or it could mean more of the enemy was coming, and they would be overrun. Some would call it a tactical retreat; others would call it running away. Regardless, they were to exit the area immediately, and regroup. No arguments.
Then there was another 'stand down'. That was when Optimus wished to fight, whatever enemy it was at the time, himself. Sometimes this was more of a duel, and they were to stand back, but be wary. Trickery was not new in this war, and they had to watch out for their Prime.
Override, WingSaber, Vector Prime, and Evac, also knew of another reason why Optimus may use this particular order, and it was not a good one. After Megatron had taunted Optimus Prime, and compared the tactics of his team to the use of henchmen that Megatron was more familiar with, Optimus had lost faith in his abilities as a leader and had insisted on fighting on his own so the team wouldn't get hurt. The Autobots could not let that stand; it put their leader in unnecessary danger. If Optimus was ordering them to stand down in order to protect them, at great risk to himself, it was their duty to ignore the order completely.
Then there was the third reason, and it was by far, everyone's favorite. This 'stand down' was uttered in battles when some of them were trying their best to stop the Decepticons from doing whatever it was they wished to do. This order from Optimus was not of self-sacrifice, nor of defeat or retreat. This order was not so much of a 'stop fighting' as it was 'get out of the way'.
When Optimus gave this order to stand down, it was because a large, semi-tractor-trailer-fire-truckload of hurt and payback was heading Megatron's way. When this order was spoken, it was the Autobots duty, and great pleasure, to stand back and enjoy the fireworks.
,.,.,.,.,.,.,.,.,.
Just a little fic that came to me after I re-watched Transformers Cybertron. That was my first Transformers cartoon. Ah, memories! =^-^=