An extended mx delay at their biggest hub? No excuse for that unless there's an engine about to fall off, flat tire, something major, and the article isn't clear what it was. But if it was waiting for a tech to sign off, then yes, no excuse. That happened at SDF last Sunday, someone had to sign off on a thing that broke on our A319 and we sat for (only) one hour past departure time waiting for that, so only oh half the plane misconnected.