This happened a few years ago. I was coming from Capetown through Johannesburg to London, and then on to Toronto. Its a long journey, the flight from Joberg to London is ~12 hours alone. When I get to the airport in Capetown, South African Air gives me some shaggy dog story about "we can't check you in for the International part". OK, no problem, I'll do that in Joberg. But, the flight is delayed, delayed, I'm starting to be nervous. But it will be ok I'm sure.
Eventually we take off, we land in Joberg. The shaggy dog story continues, I'll have to do this checkin from the International counter, outside security at the other end of the airport. OK, I bolt out, run down there. But, its closed, everyone has gone home. This will be the last flight of the day and you need to be checked in 1 hour before. Just someone mopping the floor. I assess my options. What have I got to lose?
So I run to the security to get back in. They ask for the boarding pass. I relate the above, quickly, hearing the 'final call' sounds for my flight. Eventually they wave me through, after all, they know the outbound immigration people will send me back. Great. I get through that, land at the immigration counter. I'm sweating. Same story from them, where's your boarding pass. Me, "blah blah, let me through". After a while they shrug. They're certain I've missed the flight, they let me go.
I go flying into the airport gate area and assess the options. I hear my name being called. I go running towards it. They yell "what seat sir" from a distance? I yell back "56H, don't close the door". I run, go flying through the door, onto airplane, they close the door, I take my seat.
Nowhere in this chain of events did I check-in or get that boarding pass. I'm hoping there wasn't some TSA-style airport lockdown that occurred afterwards either 🙂
The moral of the story, customer service agents are more interested in getting agitated travellers out of their face than of following process.
An international adjunct to this rule is, if their first language is not English, talk faster 🙂