That's an interesting anecdote, opting to wait 90 minutes to run the full length of 19, in lieu of eating some bumped pax -- whatever the downstrem effects were of subsequent misconnects or whatever else, that implies getting out of DCA full (or as close to it as the runway performance physically allows for your plane on that route notionally) is worth sitting the 90 minutes. Obviously as a layman, I recognize that operational conditions might have been such that the only acceptable weight reducation would have been problematic in it's own right, say a couple dozen or more pax for the sake of discussion (as in not just 6-10 pax to get juuuuust below what you can manage off of 1).