40 minutes before boarding is LATE!!!!

On the 4th of December I was in the middle of a traffic jam due to an accident in JHB. My flight was for 17:50. I arrived at the airport at 17:00, dropped my rental and ran like hell. I stood in the line like everyone else and looked up to the board saying flights close 40 minutes before. I then forced my way past everyone and when I asked if they can please print my ticket...\Sorry sir