How's that any different? He asked Obito in help of slaughtering a clan. That's like hiring a hitman and saying you're innocent of the crime.
Itachi asked Obito to help him kill the Uchihas because he needed help (Sasuke even said he didn't think even Itachi could take on all the Uchihas) and Obito was planning on attacking the Village again since the only likely place Itachi would find him is somewhere in Konoha because Itachi can't freely leave the village to explore where Obito might be. Itachi had Sasuke spared because he knew nothing about the coup and if there were other kids then neither would they so Itachi would have told Obito not to harm them plus if there were any around Sasuke age then they would have been at the Academy like Sasuke was. The target were only those who were old enough to know about the Coup which was everyone but kids at least Sasuke age (6) and lower so either there were none or Obito went on his own and killed them even if Itachi said not too.
The fvck was Hiruzen doing at the time? Hiruzen didn't even bother to negotiate and let Danzo do all the shit. Itachi and Hiruzen are both at fault. Hiruzen for letting the Uchiha be oppressed, and for letting Danzo call the shots and Itachi for carrying through like a *****.
Hiruzen was dealing with the day to day Hokage duties of assigning teams of graduating Genins from the Academy, overlooking his Anbu team, taking care of any taxes from the village, issuing out missions to many teams depending on how many mission request they received, watching over Naruto, making sure no one spoke about Naruto being the 9 tails host, trying to live a normal life, dealing with possible political matters with other villages, being a father, trying to negotiate with the Uchihas, checking how the other clans are. These are things a Hokage would typically handle as they are Hokage's that oversee everything in the village. There's also oversee the village defenses, request of new or more supplies for the hospitals and academy.
Can't blame The Uchiha's being oppressed on Hiruzen, it's not like they were being oppressed simply to oppress them. As Tobirama told Sasuke, Uchihas would lose control and run wild when they lost what they love. Are you going to be ok with living next to a clan full of people who runs wild filled with hatred since when they lose the strong love that they had, it turns to an even stronger hate. Tobirama said he seen this happen many times and Hashirama who have also defended the Uchihas when Tobirama said something negative about them didn't even interject against that. If Hashirama isn't saying no or it wasn't that bad or they were trying to control themselves then it's a serious matter.
They're ninjas, the people they love are going to die either in battle, due to battle injuries, due to illness, or do to old age. Uchihas love for that person turned to a stronger hate as Madara, Obito, and Sasuke all shown so a clan full of people like that who have all turned into hatred filled people due to losing people they loved. Hiruzen is a kind man and if he seen them able to control themselves and not be a threat to other villagers safety then why didn't he moved them back to the village in his 45 or so years as Hokage?
