Well, I can't be sure as to the exact nature. I fly out of GIG quite often but this was my first time at T2 since BA migrated there in August. I hope it was a glitch but it could be systemic; it was certainly very different to the relatively quick procedure that I had been used to at T1. I am flying BA from T2 again in about 3 weeks so I hope things have improved. Nevertheless, I will give myself 3 hours from departure to be safe. The check-in took too long, as did the security screening, but then, after all that, came departure passport control, which seemed on par with my experiences in the US in terms of a snaking line moving slowly into the distance.
As an observation, anyone who has flown domestic in Brazil from GIG can vouch for the fact that massive long queues for check-in are considered the norm here. If fact, my experience has been quite negative in that regard. My worse experience was arriving two hours before a flight to stand in a line that took well over an hour to get to the desk. Then, to add insult to injury, the staff were walking along the long line asking for passengers for flights with an imminent departure, pushing them to the front of the queue. So, having stood in line for an hour and 20 minutes, the passengers behind me at bag drop were passengers who had arrived only 2 minutes ago and ushered to the front in order not to miss the flight. Completely absurd and very common practice here.