Lagging out and rejoining game

Need help settling a debate. One of my buddies think If you lag out as the game starts and you are not in the lobby you have to restart your game and get in before the plane starts? But if your name appears in the lobby you have to wait til everyone is on the plane to restart your game? Does anybody have any insight on this? I have always thought you just restart no matter what and it’ll put you back into the game if the lobby is still up?