I know what you're seeing, but how can you say it was "clearly" a reignition? Engine plumes aren't always easily visible, especially on a tumbling solid. The thrust at the tail end of a solid's burn can be a tad erratic. I don't think the booster reignited; I think it just hadn't finished burning out yet, which should be expected and means they cannot consider this an unusual event; it will need to be considered when designing the final, production Ares 1 rocket.job1207":1tgjdyuv said:yes, well that is why the main engine took out the second stage. Splat, LOC, end of flight. You can see it clearly on that video. and it was clearly a re ignition.
To me, the first stage's burnout didn't look particularly unusual. You see exactly the same thing during Shuttle SRB sep. As docm put it, "With solids MECO is an event without clear boundaries."