The inhabitants of the Rubble make a deal with the Jackals for their survival. They assume they could make a deal with the Covenant and possibly even join. This despite the fact that the Covenant destroyed Madrigal, from whence most of the refugees came. Subverted in the fact they have an escape plan just in case it fails.
The Elites Honor Before Reason is taken to this level. Thel, who is the Sole Survivor, is so shook up by the events (particularly the fact that the leaders he so zealously followed are very much mortal beings with materialistic desires and having to kill his best friend) that it basically kick-starts his development into the warrior who would eventually become the Arbiter.