Okay, we've got tickets to Chicago, and a flight home from Boston. All we need to do now is connect the dots. We had planned to use our $50 companion ticket (soon to be a $99 companion ticket due to a recent price increase) but the price was sky high (a little airline humor) so we used miles.
At the airport, the agent had explained that it wasn't just missing connections in Seattle, that bumped us out of first class. Another factor is that when the airline changes to a smaller plane, as happens sometimes, upgraded ticket passengers are the first ones pushed back to coach, and then mileage passengers. A customer on my route told me yesterday that his son was recently bumped off a plane entirely to make room for non-revenue airline employees who were going to a company party. We agreed that the only promise the airline makes to its passengers is to not non-metaphorically urinate on them, and that's only if for some reason they don't want to.