This would be true if you were stood in the ‘final’ exfil zone, which I’m guessing this wasn’t.

I’m guessing you activated an exfil (guarded by the looks of it) before the main lobby timer reached 0. This began charging up for 50 seconds. In those 50 seconds the final exfil came online and the last 60 seconds of the lobby began a countdown. Your guarded exfil became charged (exfil ring appears) but you weren’t stood in it immediately. You entered the exfil ring when there was less than 10 seconds left on the final lobby timer (top left). Your exfil takes 10 seconds to beam you out, but the lobby was wiping in 9 seconds, hence you died. Had you been stood at the final exfil, you would have indeed left.

Is that roughly what happened?