The game ended corectly. After your Fleet turn, the game is over, and nothing can change that.
You "had your chance" to play an Outpost during your "pre-final" turn when you bought the last Colony. Normally (no Fleet) that wouldn't work, as the game is over after that turn. With Fleet it works, you could have an extra turn before the Fleet round begins.
On your "final" turn (from Fleet), this again doesn't work.