Stuff like this happens more often than people (the traveling public) realize... and you see it more in international than high-frequency domestic.

If you've got 5 daily flights to SFO and a guy misconnects, he can generally get on the next one. No big deal. But when there is only a single flight per day to a destination, they'll often hold it for connecting passengers; otherwise, they lose a precious vacation day stuck in some crappy airport hotel.

15 to 20 minutes seemed to be about the max they'd hold.