User blog comment:SayuriDarling/The Mark of Athena Official Discussion/@comment-201.81.42.152-20121123222538/@comment-3146930-20121128195413

Except I think you are underestimating Octavian's power to control a crowd. Even if they sent an Iris Message or something similar, Octavian could claim that it was some kind of magic that the Greeks are using to lure them into a false sense of security. Like he could say that the rainbow isn't really one made by Iris and the image of Leo swearing on the Styx is fake. Also, Leo isn't as good with words and would eventually be backed into a corner by Octavian in some way.

You also have to think back to Reyna's meeting with Annabeth on the top of the fort. Annabeth knows what caused Leo to blow up New Rome, but it no longer matters as Octavian has the Legion so worked up that the only thing that could stop the fighting is Annabeth's death. Reyna admits that the trial wouldn't be fair so even with evidence and promising on the Styx, I don't really think anyone would care.