Excellent point Mahlon! Both armies used spies to give disinformation to the enemy. In this case, as you said, it may be the 'reason' that they were waiting for to sway public opinion in their favor. It was well known there was a large disaffected population in the Cherokee Nation. It was well known that radical abolitionists had promoted the idea of arming slaves to take revenge (i.e., exterminate) their masters or any Southerner who was guilty by association. There were a significant number of Unionists in North Texas. This alarming information provides the reason and zeal to act.