He remained, under arms, in Afghanistan after his co-jihadists carried out 9-11. He was there in the military service of a regime at war with the USA, because that regime was sheltering the perpetrators of 9-11.
Had I found Sulayman, I would have just shrugged and told the nearest Northern Alliance guy that Sulayman appeared to be yet another Pakistani or Saudi, and let them dispatch him however they saw fit.