Although Yamato was deeply opposed to this mission and did not want Skywalker to be framed, those indirect hints were already all he could do.
Because of the Cursed Seal, every Root member was under Danzo's control, with virtually no room to resist.
Now that Orochimaru had revealed Danzo's entire plan, Yamato finally felt a trace of comfort. He felt that he had done everything he could; as for whether the Hokage could successfully escape and expose Danzo's plot, that could only be left to fate. From this point on, he would do everything in his power to complete the assassination mission, repaying Danzo for saving his life and teaching him.
All in all, Yamato was an extremely conflicted person. He possessed the conviction to protect others, yet lacked the courage to resist Danzo. Thus, he could only use this roundabout method to make himself feel a little better.
But in truth, this behavior served little purpose beyond self-consolation. If Orochimaru had not seen the situation more clearly as an outsider, seized upon a few clues, and "deduced" the entire plan, Sarutobi might never have understood Danzo's true objective.
Having heard Orochimaru's reasoning, Sarutobi now fully believed it, and his opinion of Danzo had changed drastically as well.
If Danzo's original assassination attempt had only threatened Sarutobi's own life, he would have chosen to "forgive him," as he always had. But Danzo's actions now threatened Konoha itself. Nawaki and the Kage-level experts of his faction were all pillars of Konoha's future. Should anything happen to them, Konoha's very foundations would be shaken. At best, Konoha would decline from that day onward; at worst, the entire village would be destroyed by civil strife!
Under such circumstances, Danzo's threat level in Sarutobi's mind had far surpassed Orochimaru's. Measures had to be taken