After an explosion like that, everyone from Konoha had believed Tobi must have been caught in the blast and blown to pieces. When they saw that Asuna was unconscious but still breathing, they felt deep down that the sacrifice had been well worth it. Konoha Ninja Village had lost a powerful enemy, while not one of their own had died.
But now Tobi had appeared before them completely unscathed, something the Konoha ninja found hard to accept. Fortunately, Asuna was only gravely wounded and unconscious, which offered them some comfort. If she had died, they truly would have had no way to answer to the others.
Mizuki turned and glared fiercely at Tobi, a blood-red glow rising in her eyes. "You bastard, what trick did you pull?" she demanded coldly.
"What do you mean, a trick? This was merely an unfortunate accident. In battle, things always happen that are beyond the combatants' control." Tobi tilted his head slightly, avoiding Mizuki's gaze. It was not that he dared not meet her eyes, but with the Sharingan's perceptive abilities, she might spot his own Sharingan.
If they learned now that he possessed the Sharingan, the intelligence he gave away would be far too significant. What he had revealed so far was still within acceptable limits, but exposing his Sharingan would undermine Tobi's future plans.
The Sharingan left far too much room for people to draw connections.
In the normal timeline known only to Kazemori Masaki, Obito Uchiha had controlled the Fourth Mizukage, causing the Shinobi Village to break completely with the nation's daimyo and plunging it into endless internal strife. Later, Mei Terumi, who led the resistance, discovered that the Fourth Mizukage was being controlled. After overthrowing his rule, she quickly used this fact to justify her actions, swiftly stabilizing Kirigakure Ninja