I don't think there is much benefit to crowdsourcing on-time departure information from the minuscule fraction of all AC flights experienced by FT posters. As noted above, flightstats.com keeps records.

To moderate my own expectations, I check it before my flight and find their prediction of when I will leave will usually be accurate, even while AC does not revise its prediction, or even change the display board at the gate. (Ex-MCO, you'll often see it flashing the final boarding call before the incoming aircraft is on the ground.) Tracking the incoming aircraft gives me something to distract from my impatience.

It's easy to remember all those times we were delivered "late" (and boy, would you be pissed if the flight left early and you were on time!) but how memorable is an early arrival? I was half an hour early in from FCO this week for example. (The only reason I even noticed was that I arranged a pickup for 8:45 pm because my calendar told me it arrived at 8:45 pm. However the calendar was in Euro time. I actually arrived at 2:15 - not 2:45 - Eastern. Oops.)