They asked for evidence and when the US said no they said they wouldn't hand him over.
Unlike his previous attacks, Bin Laden initially denied being behind 9/11.
Describing the faction of the Taliban that for a brief period gave Bin Laden sanctuary as a "government" seems like an unusual way to interpret the term government. It is the equivalent for us of having some bandit hiding within some cult in Maine or Kentucky and us describing that cult as the government of Maine. Also, as others in this thread have pointed out, those Taliban offered to handover Bin Laden if evidence was provided convicting him of the crime. It is interesting to compare our level of "conviction" of blame for some sets of people and willingness to accept collateral damage to civilians who happen to be around them, but when it comes to our own, even despite blowback and high levels of culpability, we deny the equivalence and block judgements even from UN courts.
Could you clarify? Upon whom? My understanding is that neither the Afghans nor the Iraqi civillians that ended up being the majority of the victims of our subsequent actions were the perpetrators of the acts on 9/11 or even from the societies that nurtured them. If I recall correctly, 15 of the 19 were from Saudi Arabia and the remaining 4 were from the UAE, Egypt and Lebanon. Even Osama bin Laden was Saudi, and nurtured in Switzerland, funded by the US Army and subsequently protected by the Pakistani Army which was itself directly funded by the US taxpayer.