No...there is no such thing as an invisible random selector. When you turn the game off and on for any game other than Emerald or a burnt out RS copy you get a new seed, meaning all the frames and such are completely different.
And you did not choose to re-land near an old shiny frame. You just happened upon a new one that was luckily the same exact species as the one you found earlier. All it is was extreme luck. That's it.
And I know you were trying to help. I just like to say something when I see false info going around. Heck, some people STILL believe Reshiram and Zekrom can be shiny at Dragonspiral tower. Rumors do not go away easily among shiny hunters.