To be fair, there was nothing in your original post that suggested that you had rebooked, and I don't think many of us automatically assume that every poster is aware of rebooking options. Yeah, the tone's a bit smartass, but it feels like you're trying too hard to pick a fight here.

More on topic (assuming you haven't decided I'm another jerk and stopped reading), how often do things like this happen? Do other flyertalkers automatically double-check availability right after they book? Should we?