Leaving Panama City the week before last was a bit of a muddle. There were two flights leaving at around the same time from adjoining gates, and it was almost inevitable that the two queues (lines) would get mixed up together. For the Iberia flight to Madrid, the queues for the various group numbers were not clearly delineated and there was just a little man walking around calling out the group numbers. Iberia should have posted signs showing clearly where people should be standing. At Tocumen there isn't enough space for people boarding two different flights to wait comfortably without confusion.
Had it not been for an alert check-in official, I might have boarded the adjoining Copa flight and ended up in Medellin!