re: Atlas 5 launch maneuvers
I believe that the movement illustrates the autopilot's mode change from open-loop to closed-loop guidance. While the Atlas V SRMs are burning guidance is open-loop. That is, the rocket is flying along a pre-programmed course. When the SRMs separate, the guidance mode shifts to closed-loop and the autopilot then begins to correct for realtime errors in the three axes. Think of it as ball-park guidance versus fine-tuning.
I'm pretty sure that's what was going on in that sequence. To be sure, I'll ask the guys who are doing Atlas V work Monday.
-Kim-