Also werent the forsaken messing up his sleep with nightmares that everyone was having? With Calandor and Balzalmon crap?

There's a bit more of a thought, he wasn't exactly getting a good night's sleep, and what little he was getting was in Tel'aran'rhiode, so not really sleep at all.  He was exhausted and paranoid, probably hyped up on adrenaline and perhaps already going a bit mad...  Talk about clouded judgment.  Besides, as I mention earlier, it was a rather suspicious group that stopped in his camp in the middle of the night. 

i always get the impression that she isnt actually a darkfriend

There is little doubt that she was in my mind, not many people travel in the company of greyman, though I suppose it could have simply used her as an unwitting distraction to aproach Rand...

Sorry, a bit late to jump back into the discussion, but where does he mention this "nameless darkfriend killed in the Murandian hills"?  I'll keep an eye out for it in this read through, but a book number would help...

Ooh, didn't think of that...  And yes, there are two occasions where Rand senses greyman, tear with Lanfear, and Caemlyn with Avi...  Add that to the other two points, and it suddenly makes more sense; he wouldn't have known what he was sensing, since he'd only just begun to channel, yet he may have sensed... something...

I've reread this series many times, but only just really took in that bit about an eleventh man. Is it possible it's a Gray Man?

Yep, look two posts up, RJ confirms it is a greyman, but leaves an unknown for why Rand attacked.

I'll stick with paranoia combined with some base (paranoid) logic, as mentioned above, what merchant would (normally) be out that late (we must assume it is rather late, since Rand has a campfire that was dying, and since he just woke from troubled sleep on a journey that would, in his paranoid state, let him sleep only when completely worn down to the nub...), and then be willing to share it with any stranger (we all know travelers have light fingers after all...)

Alright, here's the quote, sorry, it is rather large...

'Rand sat up out of his exhausted sleep, gasping, the cloak he had used as a blanket falling away. His side

ached, the old wound from Falme throbbing. His fire had burned down to coals with only a few wavering

flames, but it was still enough to make the shadows move. That was Perrin. It was! It was him, not a dream.

Somehow. I almost killed him! Light, I have to be careful!

Shivering, he picked up a length of oak branch and started to shove it into the coals. The trees were

scattered in these Murandian hills, still close to the Manetherendrelle, but he had found just enough fallen

branches for his fire, the wood just old enough to be properly cured but not rotten. Before the wood touched the

coals, he stopped. There were horses coming, ten or a dozen of them, walking slowly. I have to be careful. I

cannot make another mistake.

The horses swung toward his failing fire, entered the dim light, and stopped. The shadows obscured their

riders, but most seemed to be rough-faced men wearing round helmets and long leather jerkins sewn all over

with metal discs like fish scales. One was a woman with graying hair and a no-nonsense look on her face. Her

dark dress was plain wool, but the finest weave, and adorned with a silver pin in the shape of a lion. A

merchant, she seemed to him; he had seen her sort among those who came to buy tabac and wool in the Two

Rivers. A merchant and her guards.

I have to be careful, he thought as he stood. No mistakes.

“You have chosen a good campsite, young man,” she said. “I have often used it on my way to Remen.

There is a small spring nearby. I trust you have no objection to my sharing it?” Her guards were already

dismounting, hitching at their sword belts and loosening saddle girths. “None,” Rand told her. Careful. Two

steps brought him close enough, and he leaped into the air, spinning - Thistledown Floats on the Whirlwind -

heron-mark blade carved from fire coming into his hands to take her head off before surprise could even form

on her face. She was the most dangerous.

He alighted as the woman’s head rolled from the crupper of her horse. The guards yelled and clawed for

their swords, screamed as they realized his blade burned. He danced among them in the forms Lan had taught

him, and knew he could have killed all ten with ordinary steel, but the blade he wielded was part of him. The

last man fell, and it had been so like practicing the forms that he had already begun the sheathing called Folding

the Fan before he remembered he wore no scabbard and this blade would have turned it to ash at a touch if he

had.

Letting the sword vanish, he turned to examine the horses. Most had run away, but some not far, and the

woman’s tall gelding stood with rolling eyes, whickering uneasily. Her headless corpse, lying on the ground,

had maintained its grip on the reins, and held the animal’s head down.

Rand pulled them free, pausing only to gather his few belongings before swinging into the saddle. I have

to be careful, he thought as he looked over the dead. No mistakes.

The Power still filled him, the flow from saidin sweeter than honey, ranker than rotted meat. Abruptly

he channeled - not really understanding what it was he did, or how, only that it seemed right; and it worked,

lifting the corpses. He set them in a line, facing him, kneeling, faces in the dirt. For those who had faces left.

Kneeling to him.

“If I am the Dragon Reborn,” he told them, “that is the way it is supposed to be, isn’t it?” Letting go of

saidin was hard, but he did it. If I hold it too much, how will I keep the madness away? He laughed bitterly. Or

is it too late for that?

Frowning, he peered at the line. He had been sure there were only ten men, but eleven men knelt in that

line, one of them without armor of any sort but with a dagger still gripped in his hand.

“You chose the wrong company,” Rand told that man.

Wheeling the gelding, he dug in his heels and set the animal to a dead gallop into the night. It was a long

way to Tear, yet, but he meant to get there by the straightest way, if he had to kill horses or steal them. I will put

an end to it. The taunting. The baiting. I will end it! Callandor. It called to him.'

I always assumed it was a combination of growing paranoia, and the knowledge that now merchant would travel that late at night unless she had a VERY good reason…  But yes, I’ve always wondered the same…