I think more than one Gl at a time is a sympton of people seeing things after playing the game until four in the morning. I just finished playing a game as the Germans, I used my first Gl to build an army so I could build the Heroic Epic. I was at war about 75% of the game and had a fairly steady supply of Gl's, which I used to rush misc wonders. About 20 turns before I knew I would get fission I saved one so I could rush the UN when it came up. I was at war for those 20 turns and no Gl's showed up, but as soon as I rushed the UN I got a Gl that turn. I have had more than one GL show up in a turn but only after using the current leader to rush a wonder or build an army, my record is 4 in one turn during a 200+ unit modern armor blitz on china.
So until I see a Screenshot or a saved game that has two GL's in it I wont be convinced.