Dang ... that's a crappy reason to lose a booster. Wonder if too much got used on launch ... engines were balky on re-start ... other?
Telemetry probably told them how much they used on each engine start ... Be interesting to see how that turns out.
Rest of the flight was simply awesome.
Maybe center tank didnt get filled up enough. Or because it went higher and burned for more time than the two side boosters that detached earlier, it needed more for its descent.