And what if the night staff at the GTAA or Customs was on his way home and either didn't get or didn't take the call to go back in? You make assumptions, but I can think of 20 things that could have gone wrong that were not really anyone's fault.
Well, I'm certain that will be in line with AC's eventual claim that it's not their fault.
And that's the problem... everytime something goes wrong, AC simply collapses. It doesn't matter how big or how small the problem is, or what it is, the inevitable response is "It's not our fault."
Everyone on the planet, most domestic pets, and many higher order primates and mammals understand that things go wrong, and these things are often unavoidable and/or unpredictable. But smart people, and smart airlines, have plans to deal with these irregular operations.
AC's standard response seems to be "look busy until there's no one watching, then sneak away quickly" followed by the standard boiler-plate declaration that "it's not our fault."
I've encountered that situation regularly in the past when I was travelling through YYZ on AC. The delays ranged from several minutes to a maximum of 34 minutes, and only seemed to be resolved when I phoned the concierge and offered my phone to the captain, after both myself and the crew were repeatedly told there'd be someone there in a minute or two. This occurred on a mid-week mid-afternoon.
So the fact is it's not like this is the first time it's happened, and it certainly won't be the last. You'd think some bright light at AC would figure out a response mechanism to fix this problem in the future. But all the bright lights have either left or been extinguished by management.