In previous competitions, catching would supercede fast times (because you time is impacted by overtaking the other team). And you still wouldn't get a time when overtaken, because you'd been caught. Sometimes a winning team might continue to try and register a world record, but the result is just a win.
By being caught, GB had the slowest time. Most of this is moot in any case, they were in bits and going to finish last anyway.....
