[pg 737, A Crown of Swords, aCoS] 'Sammael had to be dead. He had to be. There had not been time for him to run, no time to weave a gateway, and if he had, Rand would have felt Saidin being worked. Sammael was dead, killed by an evil almost as great as himself.'
Is Sammael really dead? Has Rand got it completely wrong as he so often does? Did Sammael know Rand would try something and have a carefully planned escape route?
Evidence
[pg 726, A Crown of Swords, aCoS] 'One stabbed through the heel of his boot, through his heel, and he heard himself cry out as he fell.'
Rand receives a in his foot while fighting Sammael in Illian. There is continuous mention of these wound right up until Sammael disappears:
'and limped hurriedly' [pg 726]
'Hobbling into the corridor, he sank to one knee' [pg 726]
'ran limping' [pg 728]
'he hobbled away' [pg 728]
'He hurried forward as fast as he could' [pg 729]
'He hobbled after her' [pg 730]
'He limped around that as fast as he could' [pg 730]
'Rand limped after him as fast as he could' [pg 733]
'His wound throbbed; it seemed a year ago that that red wire of Fire and Air had stabbed his heel.' [pg 733]
'Rand teetered after him' [pg 734]
'Limping, he ghosted through the dark streets' [pg 735]
'every second step a stab of pain up his leg' [pg 735]
pg 736 / 737: Rand uses balefire, and Sammael seems to have disappeared.
There is no further reference of any pain, or of anything wrong with Rand. Rand notices his tattered shirt, and blood on Bashere, but makes no reference to any wounds on himself.
[pg 292, New Alliances, PoD] "He [Rand] was injured, and then not, but I don't think a sister Healed him. The wounds no one could Heal are still there." - Alanna
This must be referring to the injuries taken from Sammael - there is nothing else Alanna could be referring to. She says 'he was injured, and then not'. This matches with the repeated descriptions of Rand limping and then it mentioned no further. Somehow Rand's injuries suddenly vanished. The descriptions of Rand limping continue after Rand meets the stranger in Shadar Logoth. They continue up to the page where Rand uses balefire on Liah. Alanna's statement made it clear that Rand was not Healed by an Aes Sedai. It has been argued that maybe one of the Ashamen Healed him, but there is no mention of the wounds after Sammael's disappearance. Somehow, Rand was injured one moment, but not the next. The only way we know how to do this is balefire. Therefore Sammael must have died as a result of balefire which killed him backwards in time prior to wounding Rand.
Did Rand hit Sammael with balefire then?
Initially Rand weaves the balefire to use on Sammael. He sees Liah and unconsciously reaches towards her forgetting about the balefire. The balefire does its thing, and goes from his hands at Liah instead of Sammael. Rand realises that he has just killed Liah. He goes temporarily mad and sweeps the balefire towards the square before letting go. The square is now covered in Marshadar, which wasn't there before Rand did the balefire.
Did Rand hit Sammael as he swung the balefire madly? From [pg 735-737, A Crown of Swords, aCoS]
Liah was standing on the rubble at one end of the square. The square is surrounding on the other three sides by palaces. Sammael is lurking at the edge of the square just outside one of those palaces. Marshadar has appeared in the palace behind Sammael, and Sammael moves a few steps into the square out of the way of Marshadar.
When Rand uses balefire he uses it on Liah who is standing on the rubble. Rand sweeps the balefire down the rubble, but stops before reaching the square which is now covered by Marshadar. Rand thinks Sammael is dead because the place where he was standing is now covered by Marshadar. Clearly Rand did not hit Sammael directly with balefire.
Why is the Marshadar suddenly across the square? Answering this question involves some knowledge of how balefire works. The best example we have of balefire in action, is when Moghedien uses balefire on the boat Nynaeve is in. What happens?
Nynaeve's point of view: She is sitting in the cabin. She senses the balefire and suddenly the cabin is three quarters full of water and the boat hits the bottom of the river.
An observers point of view (Lan): The boat travels along. The balefire hits. The boat is suddenly 100 yards further back and has been sinking for a while.
The balefire hit the boat. (At time B) Part of the boat stops existing back in time. (Until time A) So now instead of the boat continuing on its normal course, the boat spends the time sinking. (From time A until B, it is sinking) The boat has gone through the time from A to B twice. Once the first time until it got hit by balefire, and again a second time when it sank. (I shall call the second time the reweave, as the pattern is being rewoven)
An important point to note is that during the reweave, basic physical principles still applied, ie the boat which had a gaping hole in it began to sink. However, Nynaeve, and all other observers were unable to act during the reweave. The actions she had taken, and the actions of all other people were the same. So to them it looked like the boat had suddenly moved 100 yards backwards and was sinking.
We now apply this to Rand's situation. The Marshadar we are told by Moiraine in tEotW 'is utterly mindless, but it can sense food'. This is confirmed by the fact that the Marshadar changed its location during the reweave - it was suddenly across the square from Rand's point of view. Rand hits Liah with the balefire. Liah dies backwards in time. We are unsure how strong Rand's balefire is, but we would have to assume it is of fair strength as Rand does not muck about when he is facing forsaken. It must also have been strong enough to have effects prior to Rand being wounded. Thus Rand's balefire must have killed Liah backwards in time to at least before Rand was wounded. The Marshadar in Shadar Logoth is attracted to people, as Moiraine says. Thus Liah's presence in the city would have made the Marshadar move in her direction. During the reweaving, with Liah gone, the Marshadar would move around the city in a different way.
Sammael takes a long time to come to Rand in Illian after Rand triggers his wards. Did Sammael go to Shadar Logoth first to set up the welcome wagon, or was that already organised? The trollocs there had to have been a last minute thing, but Sammael would have to have gone to Shadar Logoth at some stage to set up his wards, which cannot have been there when Rand visited earlier and left Liah behind. So Sammael walks around Shadar Logoth to set up his wards and organise his troops. During the reweaving Sammael is unable to react to any changes. His actions are the same as they were previously. If Marshadar's changed path put it in front of Sammael during the reweaving he would just walk straight into it without knowing. Marshadar seems the most likely thing to have gotten Sammael as the other dangers in Shadar Logoth probably have minds rather than being natural forces and therefore would not be able to do anything during the reweave. Sammael must then have died during the reweave from Marshadar and thus never wounded Rand in Illian.
Summary
Sammael is dead from Marshadar as a result of Rand's balefiring Liah. Rand is wrong again when he thinks that the Marshadar in the square killed Sammael as it appeared there and Sammael had no chance to run. The Marshadar did kill Sammael, but earlier before Rand went to Shadar Logoth.