Many people have claimed that Taim cannot be Demandred as Rand doesn't see the black cord that connects him to the DO. However Rand only saw the black threads when he followed Asmodean into Tel'aran'rhiod and even commented to himself "Those Rand had surely seen before". (TSR, p 986) I interpreted this to mean that he had never seen them in the real world. This is supported by the fact that Rand never saw the Black wires when Asmodean masqueraded as A gleeman (there can be no doubt Asmodean was Jasin Natael!!!!) In fact it even states at TSR p 991 Rand had not seen the wires since leaving the dark place. When he severes Asmodean from the DO he cannot see the wires "He formed it like a sword of Power, a sword of Light, and struck one with the sword, one with the IMAGINED wires" (TSR p 992 (emphasis mine)).